Garmin connect app has no more space, what do I do to get more space?

 When using the garmin connect app and pairing it with my garmin instinct a notification comes up saying “ instillation failed... there may be no more space on app “:or whatever,  I have loads of space on my phone and iCloud, I don’t have a huge amount on it yet, as I have only been using it since June this year. Please help!