This is probably a dumb question. I know virtually nothing about cars. I can drive in a straight line and that's where my car knowledge starts and stops.

I bought a used 2017 Mazda cx5 last year, I have one electric key fob with it. What do I do when the battery in it dies? Do I just get stranded somewhere? It's started to only read that the key is nearby when it's right next to the start button, so I'm wondering about the battery in it. I've never had a car with an electric start before. Thank you!

EDIT: Thanks everyone! Haha. Since theres not an obvious spot to access the battery on the fob i just kinda assumed it's like a phone, where you cant change the battery yourself unless you really know what you're doing. I appreciate the help yall! 💖