Plugins:
* https://wpschema.com/
* https://wordpress.org/plugins/schema/
* https://wordpress.org/plugins/wordpress-seo/
* https://wordlift.io/
Tools:
* https://jsonld.com/json-ld-generator/
* https://search.google.com/structured-data/testing-tool
* https://jsonld.com/
* https://technicalseo.com/seo-tools/schema-markup-generator/