First welcome to the forum!!!
Next, since 1984 when we purchased our first used TT, we have never had a RV that has tank sensors that work. Clean the tanks well, learn how much they hold with your useage, learn the sounds of "full", then go dump.
The Search engine here has LOTS of threads on this very subject, go to the top of the page and try the Search button.
Some have suggested a tank sensor that mounts from the outside, stating these are remarkably accurate. For now, I think Al and I will save the $$ and just go by the experience and the sounds!
May you have many happy days in your rig!