Using Avtex AMR994/5 as a Club WIFI Repeater

Hi all. Just had an Avtex AMR995X (5G version) fitted to my van. The mobile functionality works a treat. You can also use it as a wifi repeater for local wifi. The site I'm on has poor phone reception so I'm trying to connect it the club wifi. That should be doable, but I can't get it to work.

When you connect to the club wifi through a phone, there is initially no password, but it then passes you to the sign-in page where you enter your email address and password.

When I try to connect via the router, I select the club wifi, but it is asking me for also enter a wifi password and it won't allow me to leave it blank. I don't understand why.

Has anybody else had success connecting in this way??