Enable Versioning on SharePoint Online Site Task List

By default the versioning of a SharePoint Online Site Task List is off, if you want to enable it, follow the below step-by-step process,

• Step 1: Navigate to your Task List on your SharePoint Site.
• Step 2: Now on the top ribbon select List
• Step 3: Under General Settings select Versioning settings
  
• Step 4: Now under "Item Version History" for the question "Create a version each time you edit an item in this list?" choose the yes radio button.
• Step 5: You would see that the text field next to "Keep the following number of versions:" will be enabled, add a number - say 20.
• Step 6: Optional: If you also enable Content Approval - "Require content approval for submitted items?" you can also enable "Keep drafts for the following number of approved versions:" and add a value there.
• Step 7: Optional: You can also set the draft version security.
  
• Step 8: Click save.