How to include a Period (.) after the number in the TOC table

I’m using a Table of Contents on my blog but the number list is coming up without a period after the number. Like this:

1 best product a
2 best product b
3 best product c

I would like it to have a period after the number. Like this:

1. best product a
2. best product b
3. best product c

Does anybody know how I might achieve this?

Thanks a bunch for your help!!!