Collecting data on trans men in particular in that region is very hard, but there is some information here.
Not information gleaned from finding, let alone talking to them. The only time they are mentioned on their own, not subsumed into a general LGBT group (or SOGIESC as these researchers call it) is on page 63:
No targeted services for trans men were identified, despite their having complex protection, health, and other needs. Trans men may be targeted for rape and forced marriage, and some have children as a result. Yet they are often uncomfortable accessing sexual and reproductive health services oriented to women, and may be isolated from other refugees with diverse SOGIESC and therefore not attuned to available services. “Olivia,” a trans refugee woman, said, “Trans men want to be alone and stay by themselves. We don’t meet them very often. They want to be in their own safe space as trans men.”
I have quoted the passage in full, because it tells us two things: female transgender people exist in the region and there are so few of them that not only could these researchers not find any (they couldn't find individuals and they couldn't find any groups or communities of them), but although there are now a number of services and organisations supporting male transgender people, there are none for female people.
That the researchers couldn't find any female transgender people to talk to is remarkable, because they did manage to find and speak to hundreds of male victims of rape, including male homosexual victims and male transsexual victims, all of whom come from a culture where being known as a male victim of sexual violence comes with extreme social repercussions for the entire family of a victim. That suggests the problem did not lie with the researchers not being able to build trust within the community, but with the vanishingly small numbers of female transsexuals in their target region.
From reading the report it is also clear that the people being interviewed are homosexual transsexuals. The prevalence of homosexual transsexuals amongst the female sex is 1 in about 34,000. Not 1 in 100. (The estimate in the US is 1 in 2000 to 1 in 100,000.)
This is not hard to explain - in the region, the doctrine of gender identity hasn't gained traction yet, so the few people who do socially transition do so because they are transsexual and seeking to minimise their gender dysphoria by doing so. (Access to medical transition is extremely limited, and many transsexual people find accessing general healthcare very difficult, too, due to discrimination, motivated mostly by homophobia.)
We haven't argued that female transgender people do not exist in the region, of course, but that they are so vanishingly rare in the communities Hibo is trying to reach, that there is no logical reason for her to change her language to appease followers of the doctrine of gender identity. Especially when this hinders the clarity of her message: this is something only women and girls have to endure. And only women and girls.