How to actually use the generated markup
Paste the copied script tag anywhere in your page's <head> or <body> — most CMS platforms (WordPress, Wix, Shopify, Webflow) have a "custom code" or "header scripts" field for exactly this. The important discipline is matching the schema type to the page: Organization typically belongs on your homepage or about page, LocalBusiness on a location or contact page, Service on the individual service pages it describes, and FAQPage only on pages with a genuine, visible Q&A section — search engines can penalize markup that doesn't match visible page content.
This tool checks that required fields are filled and that the output is syntactically valid JSON, which catches the two most common ways hand-written schema breaks (missing fields, trailing commas) — but it doesn't replace running your final markup through Google's Rich Results Test before publishing, since eligibility for specific rich result types has additional requirements beyond basic validity.
For the broader SEO strategy this fits into, see SEO and local SEO, and pair LocalBusiness markup with the local SEO & GBP grader to check your Google Business Profile fundamentals at the same time.