1) Ensure the .dotm Template Loads
In Word, go to File → Options → Add-ins.
Under Manage, select Word Add-ins, then click Go.
Confirm your .dotm appears as a Global Template and is ticked.
If the template is not visible, confirm the Word STARTUP folder path using the VBA Immediate Window:
Press Alt + F11 to open the VBA editor.
Press Ctrl + G to open the Immediate Window.
Enter:
? Application.StartupPathPress Enter to display the startup folder location.
Confirm your .dotm is saved in that folder, then restart Word and re-check the Global Template list.
2) Add the Macro to the Ribbon
Go to File → Options → Customize Ribbon.
Under Choose commands from, select Macros.
Select your macro, then:
Create/select a custom group on the right-hand side, and
Click Add.
(Optional) Click Rename to update the button label and choose an icon.
Click OK to save changes.
3) Add the Macro to the Quick Access Toolbar (QAT)
Go to File → Options → Quick Access Toolbar.
Under Choose commands from, select Macros.
Select your macro and click Add to place it on the toolbar.
(Optional) Click Modify to change the icon and label.
Click OK.
Result
Once added, your macro button will appear every time Word starts as long as the .dotm remains in the STARTUP folder and is loaded as a Global Template.