Was anyone diagnosed with PoTS without the TTT?

I had an appointment at a long covid clinic about a month ago and I told them my symptoms (heart palpitations, dizziness especially after eating/walking/showering, fatigue, headaches etc) and they told me I had PoTS, but I had no TTT or referral to anyone else. They just diagnosed me based on the symptoms I was having. I’ve started increasing my water intake and sodium, and I am feeling a bit better, but I feel a bit worried that I’m increasing my sodium when I haven’t had a TTT to confirm the diagnosis. Do you need to have a TTT in order to be fully diagnosed?