Syntax error due to ?? on iPad Air iOS 12.5.7

[skannea]

The problem

Older iPads can't be upgraded. My iPad Air from 2013 is stuck at iOS 12.5.7. This means some newer Javascript features will never work. Instead there will be a syntax error. On an iPad this is not so easily detected, it just doesn't work. According to this nice overview the use of the nullish coalescing operator (??) is not supported. It was introduced in iOS 14.

I 'fixed' all ?? in paper-buttons-row.js. And made it work!

So, by being a bit conservative and not using the latest Javascript features this fantastic card could be available also on ten years old iPads.

However, this is a general problem with iOS devices.
In developer's pagesI is is stated there are two variants of front-end:
Latest: this build is compatible with the two latest versions of evergreen browsers and is optimized to be fast.
ES5: this build is compatible with browsers released in the last 5+ years and is optimized to be compatible.

What version of Paper Buttons Row has the issue?

2.1.3

What version of Home Assistant are you running?

Home Assistant 2023.4.6 Supervisor 2023.08.1 Operating System 9.5

What version of the Frontend are you running?

Home Assistant 2023.4.6 Supervisor 2023.08.1 Operating System 9.5 Frontend 20230411.1 - es5

Example YAML snippet

No response

Anything in the logs that might be useful for us?

No response

Additional information

No response