How can I fix a parsing error in schema markup code?

The tags should still be in the quote but not the double quote because it will conflict with the parent quote

You can try this

“name”:
“{{ page_title }}{% if current_tags %} – tagged '{{ current_tags | join: ‘, ’ }}’{% endif %}{% if current_page != 1 %} – Page {{ current_page }}{% endif %}{% unless page_title contains shop.name %} – {{ shop.name }}{% endunless %}”,