I want to use this mod in the Aternos server hosting site, but when I try to suggest it I get the error:

"This cant be added for technical reasons."

Stating this (from here):

The suggestion is not compatible with Aternos. For example, if a plugin requires an additional port, has a huge negative performance impact, or changes the online player count of a server, it can't be added.

I have no clue at what could be doing this, so I decided to open a new issue for this, maybe it is not the best place for it, if so sorry about it.

I have no idea either, nothing is blocked, open a ticket with then to get more information

This was their reason:

1. all his files are listed as beta 2. It has existed for a very short time. So even if it was technically possioble, it would not fulfill a few other requirements

What a stupid reason, I changed the files to release