I know there are a lot of similar questions, but the solutions don't seem to work.
I think that's because the button includes an image with style="height:100%;"
(but I'm not sure)
Note: the button is to use on an email, so I'd say it's better to use inline css.
My last attempt has been including a span within the button for the text only:
<button style="height:100px; font-size:24px; color:white; background-color: #4CAF50; "><img style="height:100%;" src="https://i.imgur.com/XcXLJBA.png"> <span style="margin-bottom: 20px; line-height: 150px;">Send WhatsApp</span></button>
The output is this:
I've also tried to add to several places (with no result): display: table-cell; vertical-align: middle;
I've not more ideas. How to center that text vertically to the center?
to demonstrate my earlier comment
img,span {vertical-align:middle; }
<button style="height:100px; font-size:24px; color:white; background-color: #4CAF50; "><img style="height:100%;" src="https://i.imgur.com/XcXLJBA.png"> <span >Send WhatsApp</span></button>