Does this program offer ESL certification?

No it doesn't. It offers opportunities to co teach alongside Colombian teachers in different settings

You are provided with about 40 hours of Teaching English in Colombia training that is specific for the situations you might encounter within classrooms here, but that is the only formal instruction the program offers. Heart for Change will supposedly be offering a discount on an online TEFL certification program for the upcoming semesters, but that is optional and independent from your duties as a fellow.