Some countries allow HRT (even if only a mild dose) as a replacement for antidepressants and anxiolytics (used to treat symptoms that so often come with gender dysphoria), because there seems to be an above-placebo effect of making a transgender person feel better about themselves. There is no scientific reason for that (because this happens both for MtF and FtM transgender people), and, as said, it will not happen in the same way for everybody, but allegedly it helps.
In my own country, even if the scientific reports about this strange effect are well-known, you can only get on HRT if you commit to a full transition with a real life test. Otherwise, you just get therapy, antidepressants, anxiolytics, etc...