Hi @johnjohn123 - Please see attached .msapp file. Save it locally and then open it directly in Power Apps.
Open Power Apps and select create and select canvas app from blank as shown...

Then just give your new app a name, any name, doesn't matter at this stage:

On the next screen select file:

Select open and then browse to select the msapp on your local drive adn then select 'dont save' when prompted about unsaved changes

First thing when the app opens is do a save as to the cloud.
Then, you can start modifying the app - If you want to change the text contents of the controls, go to the 'Onvisible' property of 'Screen 1' as shown and just amend the text between the double quotes to suit what you want to show - youj can see here also where I have just added google as a place holder URL - you just need to swap this out as required. I am collecting this table into the Collection 'colSPOButtons' onvisible of this screen and this collection is then bound to the 'Items' property of 'Gallery1'.

Once you are happy with your revised app, be sure to save and publish it. In the following screen select 'See all versions'
Then Select 'Details' and copy the 'App ID' (you need this to embed the app in SPO) - Note also the 'Share' button in this screen, which is how you share this app with the required users. This is something I should have mentioned which may put you off using Power Apps for this use case - you will need to share this app with all required users of the site. If users cannot access the app, they will be met with a blank permission denied type notice in your SPO site page. Also stating the obvious, but users will also need to have their powerapps licence enabled in order to access the app, I know some orgs can have power apps/automate disabled for all by default in their enterprise subs.
It is possible to share the app with O365 groups (only if they have been security enabled or Azure Security groups) - If you have either of these types of groups, you can just include the group in permissions for both your site and app and just manage permission once in the group.

Once you're done with all this, you can embed it in SPO. Go to your page, add the power apps web part and just paste the App ID where prompted in the top right:

You may or may not decide to go down teh power apps route, but either way at least this will allow you to make an informed decision - you never know, you might decide to turn the whole thing into an App! 😁
Hope this helps, but come back if you have any queries - Good luck!