Seeking advice for SDE

Hey Everyone I am currently working as full stack developer in a startup from last 1.5 year. But now I am not learning so much while working on frontend side and find it boring which also make me unproductive. I love to write logic and do the work which challenge my ability and push my boundaries. So should I leave this job but I don't have any other offer in hand I am planning to work more on backend side learning new language and then apply to other companies. Can you please help me to figure out this

P.S: If you have any openings for backend role then I would happy to discuss it more

Thank you