Give it a look at [plugin-session-sharing]:
https://community.nodebb.org/topic/7829/nodebb-plugin-session-sharing-session-sharing?_=1662848309040

So, I managed to get it working. Just coming here to post what works for me if anyone have the same issue. I try to scape double quotes, stringify, etc.

I had to "unfold (?)" the admin object and then all start working:

{                                                          
	"url": "${URL}",                        
    "port": "${PORT}",  
	
	"admin":{
		"username": "${ADMIN_USERNAME}",
		"email": "${ADMIN_EMAIL}",
		"password": "${ADMIN_PASSWORD}",
		"password:confirm": "${ADMIN_PASSWORD}"
	},

	"database": "${DB_VENDOR}",                                	
    "${DB_VENDOR}": {                                          
        "host": "${DB_HOST}",                        
        "port": "${DB_PORT}",                                    
        "username": "${DB_USER}",                            
        "password": "${DB_PASSWORD}",                     
        "database": "${DB_NAME}",                              
        "ssl": "${DB_SSL}"                                     
    }                                                      
}                                                          

@baris Thank you, its xaponeis1

They already fix it.