Uber is helpful, but whats the deal with tipping?

I could not find a clear answer for this question anywhere on their app or site; I had to get it through other unrelated pages. Uber apparently claims to not allow tipping through their app because they want their services to be "cashless," but that makes no sense, because if I want to tip my driver (which I do; drivers deserve tips since they pay for their own gas and vehicle maintenance), I have to give him/her cash since theres no way to add a tip to my debit card. Make sense? Please make adding a tip to our fares an option, because I dont always have cash on hand!

flcx about Uber, v3.239.4