If the numbers are like this, how can I change them uniformly to 1.2.3.4.5.6.7~~~~~~20?

Thank you for asking .

Instead of changing what already exists, go to the top menu 'Utility', then execute 'Text > Linear Continuous Numbers'. Choose the first character as '1' and press Enter three times. Then select the starting point, set the spacing, and as you move the mouse to the right, you'll see the numbers increasing continuously. Click the left button to end the command when you reach the desired position.

Thank you!