Androsexual
Attraction to masculinity, whatever the person's gender.
Androsexual describes attraction to masculinity and masculine-presenting people, without assuming their gender. An androsexual person might be drawn to men, to masculine non-binary people, and to trans men.
Like its counterpart gynosexual, it exists because most orientation words need the speaker's own gender to make sense. Gay and straight both do. Androsexual doesn't — it only describes the direction of attraction, which makes it workable for people whose own gender is non-binary or shifting.
It's also useful for people who find that what draws them is masculinity itself, more than any particular category of person.