Inserting text before the </body> tag

[dbltoe]

WHMCS version 8.4.1

I am playing with the twenty-one template prior to duplicating it for the final customized customer portal.  I have some script that needs to be inserted prior to the </body> tag of the main portal page.

If I insert it on line 146 of templates/twenty-one/footer.tpl, I get a partial white screen with the footer not appearing after the insertion.

Where can I place the script in order to have it "fire" properly?

THANX
john

[pRieStaKos]

With a hook.