Under the 'Insert' menu, you can insert a ready made button. Input the text you want to appear on the button, and the link, and the button will be created for you. You can link to your other sites and Google Drive for site pages or Google Drive item. Or you can enter the URL to a website (web address) where you want the button to link to.
The button is shaped like a text box, and the colour will automatically default to that of your chosen theme.
NOTE:
1. Button links to external sites will open and display in a new tab.
2. There are limited style selections available - Filled, Outline, Text.
To change the size of the button, just drag and it will snap to the nearest grid line.
Make buttons using images, and Google Drawings or any Draw/Paint Programme.
Save them as a png and upload them to the Site.
Link to the desired destination.
Make a button at https://dabuttonfactory.com/ and save it to your computer.
Click Upload in the Insert menu and select the button image file to insert it.
Click the Insert Link icon above the inserted image and enter the URL you want the button to go to.
See Update: Timeline. You can send feedback to Google to make your feature requests known.