A nurse can do it for you. They typically have more practice giving injections than MDs not that it makes much difference.
Subcutaneous injections work fine but the reason they aren't listed on the label of testosterone injectibles is due to irritation at the injection site. For me, I noticed after a few months of SC injections there seemed to be increasing inflammation that took longer to subside. I have recently switched from my midsection to the thin fat layer on my thigh. I have to gather a bunch of skin to avoid going intramuscular but so far no inflammation from this method.
It's unlikely a healthcare practitioner will veer from what the label tells them to do. With a little education you can safely administer your own injections and be supported here by our community.