If you already have Google Tag Manager added to your site, installing the Plannit scripts for the web integration can be done by adding a Custom Tag for the Widgets and Bot (no matter what CMS or website host you have).

In Google Tag Manager, go under Tags, click New to create a new Tag:

Click Tag Configuration and choose Custom HTML as the tag type.

In the HTML field, enter your Script for the Widgets and the Bot, like below :

Scroll down and click Triggering, then choose All Pages

Enter a name for your Tag, like Plannit Widget and click Save

Submit your changes and you're good to go.