and buy from the preferred online supplier of your choice. The small RJ11 plug goes into the back of the hub and the BT phone socket in the white section is where you plug your phone in. These are all fairly generic items. Higher cost does not necessarily mean a higher quality item! Some old phones may require a ringing capacitor in the adapter (which would be mentioned in the product description) but most modern phones do not require this.
If you are not in a rush, wait here for one of the forum team to pick up. In some previous cases on the forum, they have been able to arrange a passing technician to put one through the door for customers without one. They may take up to a week to reply.
Welcome to our Community and thanks for your first post - sorry that you're having some issues with your landline currently.
I have located your account from your forum information and can see that you have had our VOIP landline since your installation; have you ever had a working landline as usually this connector is supplied at the time of installation?
At the time of checking, we are having some issues connecting to the Hub and our services are showing be offline; can you please confirm if all is working ok with your Hub as we may require a technician visit. They would also be able to check your adapter if needed.