"To find an alternative" means to search for or discover another option, choice, or solution when the original one is not available or suitable. Full definition
We have a very good squad that is weak in one or two areas, not completing this squad, not finding alternatives for those weak spots, year after year is unacceptable. (justarsenal.com)
Do all you can to keep this up, even if it means finding alternative ways of communicating apart from phone calls, emails, and text messages. (ourfamilywizard.com)
That's why they need to find an alternative source of calcium. (pandavita.com)