How do I join the MSSP?

Here is the link to the MSSP. aminoapps.com/invite/NMJEEEL0PD
The MSSP is only available on amino as of now, but in the future it will only be amino and roblox.

[@anaïs_shines_bright]

I joined!

[@germanfarie]

Imma join :D!

[@faithoshakuade5865]

Awh its not letting me join

[@anaïs_shines_bright]

Can I join even if I am 11 yrs or is it 13+ or smth