Your character is required to be of adult age for it's species.
Races allowed in Domos
This excludes all the Dragonmark houses and UA content.
Ability Score Increases (Tasha's)
The Ability Score Increase Trait in a race reflects an archetypal bit of excellence in the adventurers of this kin in D&D's past. For example, if you're a dwarf, your Constituion increases by 2, because dwarf heroes in D&D are often exceptionally tough. This increase doesn't apply to every dwarf, just to dwarf adventurers, and it exists to reinforce an archetype. That reinforcement is appropriate if you want to lean into the archetype, but it's unhelpful if your character doesn't conform to the archetype.
If you'd like your character to follow their own path, you may ignore your Ability Score Increase trait and assign ability score increases tailored to your character. Here's how to do it: take any ability score increase you gain in your race or subrace and apply it to and ability score of your choice. If you gain more than one increase, you can't apply those increases to the same ability score, and you can't increase a score above 20.
For example, if the Ability Score Increase trait of your race or subrace increases your Constitution by 2 and your Wisdom by 1, you could instead increase your Intelligence by2 and your Charisma by 1.
Flying Speed*
Races with inherent flying speed only gain this feature after reaching level 5. Before this point they may only use their flying speed on their turn, after which it immediately ends, causing the character to fall back to the ground if they're still in the air.
Human Variant**
The following feats are not allowed to be chosen upon character creation with variant human:
The feats that are already banned, outlined in Feats
Sharpshooter
Great weapon master
Fey touched
Shadow touched
Sentinel
Custom lineage is not allowed.