has_tag() function doesn’t seem to play nice with plugin

Hello,

I’m not sure if I’m being an idiot (probably!).

I’m trying to run a script on WooCommerce products if a product has a tag ‘Canonical’.

The script executes fine if I use the conditional function is_singular(‘product’).

The script doesn’t execute at all if I use the conditional function has_tag(‘Canonical’).

Am I missing something really obvious?

I need to run the script if a product has a tag ‘Canonical’ applied to it.

Thanks