Adding Activities to the Lightning Record Pages

Navigate to Setup > Object Manager > Select the Object you'd like to enable Activities on

In the Details section, select Edit

In the optional features section, check "Allow Activities" and click save.

From the Object Manager, select "Lightning Record Pages", select the appropriate Record Page (if there are multiple, check "View Page Assignments" to be sure you edit the appropriate one)

If this is the Managed Record Page, click "Clone"

Click into the main section of the Record Page and click "Add Tab".

Select Tab Label = "Custom" and enter "Activities" as the Custom Label

Click into your new Activities Tab, then drag the "Activities" component from the components toolbar onto your page

In the upper right hand corner, click Save then "Activate"

Navigate to the Page Layout and add the "New Task" and "Log A Call" to the Page Layout. (Note: be sure you are selecting the Actions with the prefix "i360core" in the Name.)

Navigate to a record of the object you just modified and verify the tab is working correctly.

If you see this error message, you will need to remove the "Activities" component from the Lightning Record page, the "Log a Call" and "New Task" buttons from the page layout, Save and re-add these to the Lightning Record Page and Page Layout and Save again.