Text
From your Shopify admin, go to Online Store -> Themes.
Find the theme that you want to edit, and then click Customize.
Scroll down to Popup group at the bottom, Click Add section and choose "Toolbar mobile".
From the side menu, select Newsletter popup. Click + Add block and select "Text" block, or click the Search bar to enter a search term.
Text
Add text to display as a custom content (Leave the field blank to hide the custom content)
Text size
Font size of text:
Default
XX-Small
X-Small
Small
Medium
Large
X-Large
XX-Large
XXX-Large
Text (Color)
Set the text color for this block
Block padding
Top margin
Determines the height of the top outside space of the section. Can be from 0px to 100px, increasing arithmetically of 1px (pixel).
Bottom margin
Determines the height of the bottom outside space of the section. Can be from 0px to 100px, increasing arithmetically of 1px (pixel).