I have the inreach mini but no computer . How do I update firmware and software using my android phone or iPad . Thanks for your help

The situation for the Mini is exactly the same as for the 66i. Updates are delivered by Garmin Express via a wired USB connection to a desktop computer. You will have to open a support ticket to find out if OTA updates via WIFI, possibly with an assist from one of the free mobile apps, is possible. 

Hi . Many thanks . What’s a support ticket please? 

The forums are not an official Garmin support channel. Sometimes a Garmin employee will respond to a forum post, usually with a link to a relevant support article. To get direct support for an issue, or to get an answer to a specific technical question, you must contact Garmin support for help. That "help request" is a support ticket.

They don't make it easy to find out how to do this. For the Mini, use the Chat or Call buttons at the bottom of this page:

https://support.garmin.com/en-US/?contactOverride=true&productID=592606&tab=topics

Some day, we'll all figure out how they EXPECT us to get to that page. It always takes me three or four tries to do it.

Edited to add: Sometime there's also an Email button. Based on forum feedback, I'd avoid that one. Seems to be a black hole from which answers never emerge.