Change Post Eligibility Time setup auto republish less than 30 days old posts

Where to find file settings-fields.php?

Can you edit code below and tell me where change line in code to get results in my question topic

Go to wp-content\plugins\wp-auto-republish\admin\settings-fields.php on line 99 and add this line $items = apply_filters( ‘wpar_republish_eligibility_age’, $items );.

Before: https://prntscr.com/mfrge4
After: https://prntscr.com/mfrgzc

And then add this snippets to the end of your active theme’s functions.php file:

add_filter( ‘wpar_republish_eligibility_age’, ‘wpar_add_custom_age’ );

function wpar_add_custom_age( $items ) {
$item = array(
‘1’ => __( ‘1 Day’, ‘wp-auto-republish’ ),
‘2’ => __( ‘2 Days’, ‘wp-auto-republish’ ),
‘3’ => __( ‘3 Days’, ‘wp-auto-republish’ )
);
return array_unique( array_merge( $item, $items ) );
}
This will add options like this: https://prntscr.com/mfrfby. Then select resave changes.

Thanks!