how to disable Robo killer on an iPhone

Hi cherise53, thank you for posting here in Apple Support Communities. We understand that you're looking to disable the third-party app RoboKiller on your iPhone. To help with what you're looking to accomplish, we recommend that you reach out to RoboKiller's support directly. Here's how: RoboKiller's Support Help Center

If you're looking to remove that app from your iPhone completely, here's a great resource that you can reference: Delete apps on your iPhone, iPad, and iPod touch - Apple Support

We hope this helps.

Take care!