Grid Layout is only available for paid plan, starting with the MINI at just $0.99/month
While Lnks can only have one style, you can use the Buttons Block to add additional Lnks on top of your Grid.
If your Lnks are not yet in the Grid format, please follow this guide to do so.
Then head over to the Style section, locate your Lnks grid and tap on the purple Plus button over it a shown below:
Once you tap on in, select the Button block as shown below:
Finally add a Title and a Lnk for your button.
Repeat this for as many buttons you want to create.