Yes, possible.
We assume you are using a Time Capsule with internal disk not the Airport Extreme?
How old is this Time Capsule.. because the wifi speed suggests you have an older model?
By far the easiest solution is to plug a USB Mac formatted hard disk into the computer. Faster and more reliable.. for Catalina almost I would say required.
Plugging the TC straight to the computer by ethernet is possible.. if really not the best way and fairly complicated.
Plugging the TC into the router is possible but again can be unreliable. The setup is easy enough if you do understand a bit about networking.. otherwise honestly the USB drive is much the easier.
Tell us and we can give you some details.. but the starting point is fairly easy.
Plug the TC into the new router with ethernet. Reset it and run through the setup. Use short names, no spaces and pure alphanumerics for everything. Password same rules but longer.
Once completed turn off the wireless.
Once you complete that it should be available over the network.. but then it will disappear after a day or so due to some poor network choices Apple made. We can fix those.. if you get to this point.