Router log in details

Hope this is the right place for my query.
I am going to replace the Talk Talk D Link DSL-3782 with a TP Link AC1900 (Archer VR900 ) router/modem.
There comes a point in the TP Link set up using ethernet cable where you need to input user name and password, which you get from your ISP.
User name is the phone [email protected]. What though is the password? In my Talk Talk account I have a phone number that purports to give you this if you call. I tried and I'm not convinced the person understood what I was asking for.
From what I could gather the password would be the wireless password from the D Link router/modem.
Any help in clarifying this would be most welcome.

My understanding is that there are a couple of misleading statements within the TalkTalk help pages, referring to the username and password and giving a number to call as you said. They used to be required, but they are not now, it changed a while ago but the help page has not been updated.

TalkTalk authenticates your connection automatically just using your phone number, according to a recent post on the TalkTalk Community - I don't have a link to hand.

Have you tried leaving the fields blank? If the router needs the fields to be filled, anything at all will do, a random word or number should be fine.

It has been a long time since I used TT but I think the previous poster is correct. TT use your phone number to verify your connection so just leave the fields blank.

The TT community forum is here. They are generally very helpful.

Many thanks for the advice given. I have also joined the TT community . New router arrived and it was a simple matter of disconnecting the old and plugging in the new. I may have been over cautious but rather that than end up making a pigs ear of things.
Once again thanks to all who gave advice and nice to know there are places to go for reliable advice.