When Single User Logged In One WordPress Site then user can automatically Logged-in other User’s related site

Solution:

Our goal is to set up two WordPress websites which will share logins and the same users. Once a user has subscribed one

website, she would be able to access the other website with the same role and capabilities.

step 1: In order to share the same users and usermeta tables, WordPress installations must share the same database. add prefix of first wordpress installation first_ and second wordpress installation table second_. in same database.

step 2: When the first WordPress website is up and running, we can edit its configuration file. Open /first/wp-config.php

and add the following lines above the ‘stop editing’ comment:

 $table_prefix  = 'first_';
 define('WP_DEBUG', true);
 define( 'WP_DEBUG_LOG', true );
 define( 'WP_DEBUG_DISPLAY', false );
 @ini_set( 'display_errors', 0 );  

// custom users and usermeta tables
define( 'CUSTOM_USER_TABLE', $table_prefix . 'users' );
define( 'CUSTOM_USER_META_TABLE', $table_prefix . 'usermeta' ); 

/* That's all, stop editing! Happy blogging. */

step 3: We are done with the first installation. Next we have to copy wp-config.php from the first installation folder and

paste it into the root folder of the second installation. Be careful to change the $table_prefix value accordingly:

open /second/wp-config.php.and add the following lines above the ‘stop editing’ comment:

 $table_prefix  = 'second_';
    define('WP_DEBUG', true);
    define( 'WP_DEBUG_LOG', true );
    define( 'WP_DEBUG_DISPLAY', false );
    @ini_set( 'display_errors', 0 );

      // custom users and usermeta tables
     define( 'CUSTOM_USER_TABLE', 'first_users' );
     define( 'CUSTOM_USER_META_TABLE', 'first_usermeta' );

step 4: write in both wp-config.php for sharing cookies.

    //Share cookies
   define('COOKIE_DOMAIN', '.xyz.com');
   define('COOKIEHASH', 'aee53c017c29dc0d3ae37253fc8cbfd8');

step 5: Open table “first_usermeta” and copy from column meta_key – first_capabilities and first_user_level to the second_capabilities and second_user_level.

step 6: When running the second installation, we should set a non-existent email address for admin user as WordPress finds a number of existing users from first_users table.

For more Detail https://kinsta.com/blog/share-logins-wordpress/.

It’s work for Me.