like button from anonymous

Good afternoon,

I installed the like button successfully, or at least I think so.
I used the theme curiosity lite.

the main issue is that votes from anonymous people are not taken into account.

there is this line in the plugging:
Make sure not to disable anonymous access to /wp-admin/admin-ajax.php,
otherwise votes from anonymous visitors will not be accepted.

the link does not work.

can you advice how to solve the problem?

thanks for your help
regards
Stephane