Activate the Admin Token for Vaultwarden

Hello there.
I am trying to activate the token admin thingy for vaultwarden but it’s without succes so far.
Keep getting : “The admin panel is disabled, please configure the ‘ADMIN_TOKEN’ variable to enable it”
According to those topics : Enabling admin page - Help - Vaultwarden Forum (formerly Bitwarden_RS)
How to enable admin page on vaultwarden? · tteck/Proxmox · Discussion #250 · GitHub
I have tried to locate “conf.json” to change it, can not find it. Found many other forums/topics with more or less the same answers but same result.
Went in to /home/umbrel/umbrel/app-data/vaultwarden but no config file or anything usefull.
Could not find anything on this forum too :slightly_frowning_face:

I run out of ideas to do, anyone could activate it ?
I’m basically trying to set up SMTP and would like to change/verify the settings.