domain.com
A record

+-----------+---------------------+
|   Host    |          @          |
+-----------+---------------------+
| Points To | 35.185.44.232       |
+-----------+---------------------+

To Verify your domain Add TXT record
TXT record

+-----------+-----------------------------------------------------------------+
|   Host    |                                @                                |
+-----------+-----------------------------------------------------------------+
| TXT Value | gitlab-pages-verification-code=00112233445566778899aabbccddeeff |