Plugin for URL shortener

Sloppy code dude. You must to read docs carefully before you do something for very first time Creating Options Page

Replace your settings code with this:

add_action( 'admin_menu', 'register_shortedga_menu' );
function register_shortedga_menu()
{

    // Add as submenu item of Settings main menu
    add_submenu_page(
        'options-general.php',
        'Shorted.ga',
        'Shorted.ga',
        'manage_options',
        'shortedga',
        'shortedga_settings_page'
    );

    // Register settings at admin_init only on options pages
    if (
        !empty( $GLOBALS['pagenow'] )
        and (
            'options-general.php' === $GLOBALS['pagenow']
            or 'options.php' === $GLOBALS['pagenow']
        )
    )
    {
        add_action( 'admin_init', 'register_shortedga_setting' );
    }

} // eof register_shortedga_menu

function register_shortedga_setting()
{

    // Now do register setting
    register_setting(
        'shortedga', // Group, used for settings_fields()
        'shortedga' // Option name, used as key in database
        // It's a good practice to do option sanitization here
    );

} // eof register_shortedga_setting

function shortedga_settings_page()
{

?><h2><?php echo $GLOBALS['title']; ?> Options</h2>

<form method="post" action="options.php">
<?php
    // Prepare form sections
    settings_fields( 'shortedga' );
    do_settings_sections( 'shortedga' );

    // Fetch existing options
    $option_values = get_option( 'shortedga' );
?>
<table class="form-table">
    <tr>
        <th scope="row">
            <label for="shortedga[id]">Your <em>Shorted.ga</em> ID</label>
        </th>
        <td>
            <input type="text" name="shortedga[id]" id="shortedga[id]" class="regular-text" value="<?php echo $option_values['id']; ?>" />
        </td>
    </tr>
    <tr>
        <th scope="row">
            <label for="shortedga[tip]">Type of Links</label>
        </th>
        <td>
            <select name="shortedga[tip]" id="shortedga[tip]">
                <option>-- Select Proper Option --</option>
                <option value="0" <?php selected( $option_values['tip'], 0 );?>>Family Safe</option>
                <option value="1" <?php selected( $option_values['tip'], 1 );?>>Adults Only</option>
            </select>
        </td>
    </tr>
</table>

<?php submit_button(); ?>
</form>

<?php

} // eof shortedga_settings_page

And then get option in your function with $option = get_option( 'shortedga' );

Btw, never place Option page with couple options in admin root but as submenu of Settings or Tools items.

Cheers,
Urke

I did it with this code

<?php

/*

Plugin Name: Shorted.ga Easy Link plugin

Plugin URI: https://shorted.ga/

Description: Just simple, if you use this plugins, your Shorted.ga EASY LINK will be added automatically, for all the external links of your website posts or pages.

Version: 1.0

Author: John

Author URI: https://shorted.ga/

License: GPL2

*/

add_filter( 'the_content', 'cn_nf_url_parse2');

function cn_nf_url_parse2( $content ) {

	$tip = get_option( 'shortedga-tip' );

	$id = get_option( 'shortedga-id' );

	$content = str_replace('href="', 'href="https://shorted.ga/'.$id.'/'.$tip.'/', $content);

	return $content;

}

add_action( 'admin_menu', 'register_shortedga_menu_page' );

function register_shortedga_menu_page(){

    add_menu_page( 'Shorted Menu', 'Shorted Menu', 'manage_options', 'shorted-easy-link-plugin/shorted-easy-link-plugin.php', 'shortedga_menu_page', '', 6 );

}

function shortedga_menu_page(){

 ?><h1>Shorted.ga Menu Options</h1>

 <form method="post" action="options.php">

   <?php settings_fields( 'shortedga-id' ); ?>

    <?php do_settings_sections( 'shortedga-id' ); ?>

    <table class="form-table">

      <tr valign="top">

      <th scope="row">Shorted.ga Menu Options</th>

     </tr>  <tr valign="top"> <td>Please add your Shorted.ga ID<br /><input type="text" name="shortedga-id" value="<?php echo get_option( 'shortedga-id' ); ?>"/></td>

	    </tr>
    </table>

    <?php submit_button(); ?></form>

<form method="post" action="options.php">

	<?php settings_fields( 'shortedga-tip' ); ?>

    <?php do_settings_sections( 'shortedga-tip' ); ?>

    <table class="form-table">

<tr valign="top">

<td>Please write correct type of links "0" for Family Safe and "1" for Adult links<br /><input type="text" name="shortedga-tip" value="<?php echo get_option( 'shortedga-tip' ); ?>"/></td>

      </tr>

    </table>

    <?php submit_button(); ?></form>

<?php
}

function register_mysettings() { // whitelist options
 	 register_setting( 'shortedga-id', 'shortedga-id' );
	 register_setting( 'shortedga-tip', 'shortedga-tip' );
}
add_action( 'admin_init', 'register_mysettings' );

`
This works perfect for me and for every version of wordpress. How can I post it to Plugin page???