We know that the one wajib thing a wife must observe towards her husband is "tamkīn", which means sexual availability.
Of course, this does not mean the husband can "force" himself onto his wife, or what is known in today's society as "marital rape". If this was the case, and the husband forces himself on the wife, then in reality their marriage has already failed and fallen apart.
A healthy husband/wife relationship also depends on their physical attraction towards each other and sexually satisfying each other. This is why the wife should aim towards sexually satisfying her husband, and the husband should also cater to his wife's needs.
Both also need to be considerate of the physical, mental and emotional state of each other. If she or is sick, or not in the mood, or upset for some reason, or tired, or anything else, and it's not an ongoing excuse, then they should be considerate and respect their spouse. Be patient, be understanding, think beyond just sexual satisfaction, and build the relationship between you and your spouse.
Of course, it should never be to humiliate or extract revenge or get back at the spouse. This would be sinful and haram.
Intimacy has its value when both sides are enjoying, and hence both the husband and wife should aim towards living together with a healthy intimate life and also adhere to what our Islamic akhlaq and laws wants from us.
With prayers for your success.