Locked out of Website

I cannot reproduce the issue: I created an Editor user, installed the plugin and switched to that user and it worked as expected.

What error do you get when you access your /wp-admin/ URL?
Did you try to delete your cookies?

Yes, I cleared the cookies

When I try to login I get this message:
Sorry, you are not allowed to access this page

And the email I received from Ninjafirewall says:
NinjaFirewall has blocked an attempt to modify a user capability by someone who does not have administrative privileges:

Blog: https://website.com/
Username: xxxxx, ID: 2
meta_key: wp_sw_capabilities
meta_value: a:1:{s:6:”editor”;b:1;}
User IP: 161.97.232.163
SCRIPT_FILENAME: /home/customer/www/website.com/public_html/wp-admin/plugins.php
REQUEST_URI: /wp-admin/plugins.php?charsout=370&plugin=wp-user-role-switcher%2Fwp-user-role-switcher.php&plugin_status=all&paged=1&s&action=role_switcher&role=editor&nonce=688cd274b7
Date: April 29, 2021 @ 11:46:27 (UTC -0700)

A PHP backtrace has been attached to this message for your convenience.

This protection (and notification) can be turned off from NinjaFirewall “Firewall Policies” page.

There’s something that triggered the privilege escalation protection of the firewall. A script wanted to modify your capabilities.
Try first to temporarily disable the protection by adding this line to your wp-config.php script:
define('NFW_DISABLE_PRVESC2', true);

Then try to log in.

I added the code to wp-config.

I can log into the website as now there is a black bar above the website, however I cannot access the dashboard.

Perhaps I should uninstall Ninjafirewall?

How would I do this manually via ftp?

Thanks.

You can rename its folder (/wp-content/plugins/ninjafirewall).
After, you could remove the NFW_DISABLE_PRVESC2 directive from the wp-config.php.

If that doesn’t work, you may need to disable all plugins one by one. But it seems to me that your account is somehow corrupted (wrong user role or missing capabilities).