To change your new Wordify install to a Multi-Site install just requires two config changes which can be done right in the Edit Site > Config menu of the Wordy Control Panel.
The config is as follows:
To change these in the CONFIG menu, click edit on the existing config item, or create a new one to look this:
And another one like this:
Afterwards, the config should look like this:
Then log in to WP Admin to complete the Upgrade Network setup:
If you need any help, please reach out and we'll gladly convert the site for you.