WampServer

Good day. I just wanna ask this:
Can I distribute wamp with my application? It uses MySQL. Do I have to
pay for using MySQL in WAMP?

You can distribute WAMPServer, no charge

---------------------------------------------------------------------------------------------
(Windows 10 Pro 64bit) (Wampserver 3.3.4 64bit) Aestan Tray Menu 3.2.5.4
<Apache versions MULTIPE> <PHP versions MULTIPLE> <MySQL Versions MULTIPLE>
<MariaDB versions MULTIPLE> <phpMyAdmin versions MULTIPLE> <MySQL Workbench 8.0.23>
Read The Manuals Apache -- MySQL -- PHP -- phpMyAdmin
Get your Apache/MySQL/mariaDB/PHP ADDONs here from the WAMPServer alternate Repo
-X-X-X- Backup your databases regularly Here is How dont regret it later! Yes even when developing -X-X-X-

Is there any official documentation for commercially distributing WAMP Server to support my application?

If you only want MYSQL it would be simpler to distribute just MYSQL

---------------------------------------------------------------------------------------------
(Windows 10 Pro 64bit) (Wampserver 3.3.4 64bit) Aestan Tray Menu 3.2.5.4
<Apache versions MULTIPE> <PHP versions MULTIPLE> <MySQL Versions MULTIPLE>
<MariaDB versions MULTIPLE> <phpMyAdmin versions MULTIPLE> <MySQL Workbench 8.0.23>
Read The Manuals Apache -- MySQL -- PHP -- phpMyAdmin
Get your Apache/MySQL/mariaDB/PHP ADDONs here from the WAMPServer alternate Repo
-X-X-X- Backup your databases regularly Here is How dont regret it later! Yes even when developing -X-X-X-