Helo @jenirizio-1! The instructions for submitting entries are in the Categories and Rules document which you can download from Latest news on the Online Eisteddfod 2021!
The singing entries are audio only, rather than video, and they should be anonymous for the judging, so don’t give away too much here or people will know which is your entry 
If you still have questions after reading the instructions, just post again here tagging @gisella-albertini and she’ll be able to clarify things for you.
Pob lwc!