Frenemies From Forests by Ashe Moon

Perfect, powerful, and obsessed with tradition, omega Thran is the strongest warrior in a clan of reclusive forest dragons. There isn’t a challenge he can’t overcome—except for dealing with the fire dragon outsider Baleon, who’s been a pain in his ass since the day their worlds collided. Thran wants nothing to do with the showboating, freewheeling, and irritatingly attractive alpha—but a mutual need forces him into an arrangement from hell: he must learn firefighting from Baleon.
Baleon is a simple alpha who only wants one thing: to get good enough to defeat Thran in a fight. Now he finally has the opportunity to take the flawless omega down a peg and prove himself a real warrior, but when it comes time to work together with his sworn frenemy, the ghosts of their respective pasts stand firmly in the way. Baleon is resolved to break the domineering omega’s battle-worn defenses—but he quickly discovers there’s a thin line between burning hatred and all-consuming lust.