Categorizing people in terms of sexual preferences (gay, lesbian, asexual, etc.) is a modern Western phenomenon. As far as traditional Islam is concerned, sex is what people do or not do. It is not who people are. It is not the core of a person's identity.
A spouse is required to fulfil his/her duties as husband/wife.
If a man believes he can fulfil the physical/emotional needs of a woman (and his woman in particular), it is permissible for him to marry. If he has reasonable doubt that he might be unable to do so, then to the extent that he is in doubt, it becomes unadvisable for him to marry. And likewise, for the woman.
Attraction is not a requirement for an Islamic marriage to be valid, if only for the reason that it is subjective and oftentimes fleeting. Here is a narration that might be relevant:
أن رجلاً جاء إلى عمر يريد أن يطلق زوجته معللاً ذلك بأنه لا يحبها، فقال
له عمر: ويحك، ألم تُبْنَ البيوت إلا على الحب، فأين الرعاية وأين
التذمم؟ A man came to Umar wanting to divorce his wife, saying that he
did not love her, so Umar said to him: Woe to you, aren’t homes built
except on love? So where is the caring and the kindness? [1]
Check also here.