google sheets – How to generate URL from cell contents on entering values

I have column A with values such as

345722
456922
71881

I want to generate URLs from these numbers like https://example.com/id/xxxx. I want the column values to be updated and the generated URL to not go in another column.
What I mean is that when I enter a number into column A like 34000 the cell contents get automatically updated and the URL text should be the text of the cell.

I had looked at this it did what I wanted in another column and I had to drag the end of a cell with the formula so that it would work for the others.