Have multiple offers. But the one I'm most interested in is currently going through approvals and is taking time to come

Meanwhile can I accept the one that I already have and start my Visa transfer? What happens when the offer I want actually comes through? Current Visa is valid toll 2023, so while I'm not in a rush the other company has already waited over 2 weeks for me to accept the offer and I'm not sure how I can ask them for more time.