I don’t know specifically about the Point Theme, but for most themes, the way you should make a change to the theme’s code is to first create a child theme. Then you want to make a copy of the theme’s footer.php file into the child theme folder, and make your change there.
For most script code, though, you can usually use a plugin like Header and Footer. Once you install this plugin, you would go to Settings → Header and Footer and paste your code into the field labeled BEFORE THE </BODY> CLOSING TAG (FOOTER). Note that there are two fields, one labeled Desktop and the other labeled Mobile. Paste it into the Mobile field and mark the check box.