Add zero before single digit?

Question

Regular Expressions

Hello!
Row options

2:5
4:15
21:26
14:7

You need to select all single digits, and add a zero in front of them to get

02:05
04:15
21:26
14:07

/(^|\D)(\d)($|\D)/, "$10$2$3"Such an expression corrects if only one of the numbers is non-zero. And when both numbers, then only the first number is corrected.
How to fix?
https://regex101.com/r/46zqqu/1

Answer 1

все гораздо проще:
паттерн - /\b(\d)\b/g
заменa - 0$1
https://regex101.com/r/46zqqu/2

Answer 2

Как исправить?

Yes, obviously - stop using regular expressions:

[
  '2:5',
  '4:15',
  '21:26',
  '14:7',
].map(n => n.split(':').map(n => n.padStart(2, '0')).join(':'))