Hi @Yoursnani ,
Are you using a customized form or a Canvas app?
In PowerApps, we can use Launch() function to launches a webpage. We can use this function on OnSelect property of a button. However, we cannot directly edit the OnSelect property of a button in play mode, that means button is not editable in play mode.
For your requirement, I think you can set button’s OnSelect property to the value of a TextInput control, so that you can enter/edit different value(link) on this Textinput, and this button will launch to different page based on the input link.
I did a simple test for you reference. I assume you are using a customized form:
1. Below is a form created from one of my list. ”hyperlink1” is a Hyperlink column in my list. When creating this form from SP, hyperlink column will be added in TextInput control by default.
(To have a default link, you can edit its Default property)


2. Add a button under this hyperlink column, set its OnSelect property to(replace to your control name):
Launch(DataCardValue3.Text)

Check result this time. User can add/edit link in textinput, and then click the button to redirect to the link.
Best regards,
Allen