No, you cannot.
As I explained here, that's just not how the categorical imperative works.
1. For any application of the categorical imperative, you need a maxim
A maxim is a general practical rule which has the structure "If I am in situation X and want to achieve the goal Y, I will do Z." - a structure which hardly is to bring into conformity with sexual orientation. Sexual orientation is not an action you can perform, according to every credible scientific account of it it isn't even a choice (except for those who choose to "be" - rather pretend to be - LGTB or heterosexual out of social calculus without feeling it).
2. There are amoral behaviours
If there is no voluntary choice involved, it makes no sense to even speak of it being moral or immoral. Is it immoral for the tortured to confess to a crime they did not conduct, ie. to lie? Is it immoral to grab my spoon with my left rather than my right hand when I am alone at home? Is it immoral to have (not speaking of act according to) the character traits one has? In the latter two cases, I could construct moral reasons to work on certain things in practice, ie. in certain social contexts, but per se, these things are just amoral.
3. Being LGTB is no course of action
Morality is a social phenomenon. And it involves spheres of freedom. If two LGTB people live their lives and sexual orientation without bothering others - why should that restrict any third party's freedom in any way? If they offensively show off their sexuality in the public sphere that's another game, but there are limits to this regardless the sexual orientation. For example, there are countries where public kissing is morally and legally forbidden - for heterosexual partners no less.
4. Let's talk about sex
But hold a second, there obviously are actions involved! What about them? Having put obvious problems like public sex etc. out of the way, this is still worth additional consideration.
Let's take "If I want my sexual needs to be satisfied, I will only do so with same-sex partners". This obviously is not universally acceptable, so homosexuality is immoral to Kant, isn't it?
Well, probably not. This proposed maxim is probably simply too specific to actually be a maxim of the kind Kant had in mind there (for more detail and sources for further reading, see the link above). If you take "If I want to satisfy my sexual needs, I will only do so in a consensual manner with the sex I prefer" instead, there is no internal or general inconsistency in having it universally adopted (as far as I am aware of).
So what's the difference here? The CI asks you exactly to step back from your very personal inclinations and demands you to adopt only those acting principles (maxims) which a) are reasonable to be adopted by all rational beings and b) do not end up in inconsistencies if that happens. And, accordingly, there are maxims which allow for LGBTQ+ without any problems and if they are what you are enacting, there's nothing morally wrong with it. But if your maxims are only involving your own personal feelings and gain, this will end up being morally wrong.
Mind, two different maxims may result in the very same action, but moral worth, for Kant, is determined by the principles behind your action - your character as he calls it in later works - not the action itself.
As long as it is not enacted in a morally wrong way, sexual orientation as such is amoral. And this has nothing to do with the categorical imperative at all. And if you are LGBTQ+ wanting to have sex, you may very well act following a morally permissible maxim.