Reply To: Centre align page numbers in Table of Contents

The Paragraph Style will have that centre-aligned tab, but you need to add a tab for each entry. It’s not automated, but you can Find/Replace (in Story) so each Paragraph Return has a Tab after it.

Find: ^p
Replace with: ^p^t

Then replace all double Tabs: (to clean up if you already have tabs in there.
Find: ^t^t
Replace with: ^t

Not sure how much this helps your project. The table idea may work better, or using the Convert Text to Table/Table to Text option, you can add a Tab to the first column, then convert back to Text.