When you first install JMP, you can install the Excel add-in as shown below.

However, some people experience that they did not select the above feature when first installing, or that the JMP add-in menu disappears from Excel while using JMP.
In this case, please proceed as follows.
One. Please close JMP (if it is open).
2.Use the control panel , Select “Change” program .

3.Select “Edit” program below

4.under " Excel Reinstall “Add-ons”

The above is also explained in detail in the following link.
JMP Note 575299 - How to install or re-install the Excel Add-in for JMP® when the JMP tab does not appear in Microsoft Excel