Please follow steps below to display product specification tab on product detail page.

Step 1 :

Go to Store Admin –> Settings –> Metafields and metaobjects –> Click Products -> Click on “Add definition

Add product definition as below

Step 2 : Please navigate to your products and scroll down to the metafield labeled “Specifications.”

Add the text as illustrated in the screenshot provided below

Step 3 : Now go to product page from theme customize, Click in Product Tabs section and Add block “Specifications”.

Select dynamic source from content and click save.