Sorry, I'm just seeing this. My situation is a little different, but here's what I know.
For those AFAB of a certain age (in my case, menopausal), there is no requirement that one have been on another form of T at all before beginning pellet therapy. Pellet therapy is used for a variety of menopause symptoms. In most cases they do a mix of estradiol and T, while also doing oral progesterone. I wanted only T. They were fine with that.
For a whole host of reasons pellets were appealing to me. First, I did have menopause symptoms I wanted treated. Second, I wanted low-dose T and could do this without it raising a lot of issues at home (that's a whole other story). Third, I hate needles and the gel route was undesirable. Because I am being "treated for menopause," everything (i.e., labs and insertion) except the pellet itself is covered by my admittedly excellent insurance.
If you are still exploring pellets, there are websites that identify those in your area that provide this therapy. Unfortunately a lot of them are marketing to women pleading "please keep me young!" Ick. But, I found a place that is a more general OB/GYN and they don't play up the aging stuff as much as others. I don't know that I'm allowed to name sites, etc. here. But, feel free to PM me for more info. Good luck!