I found this helper site, which makes it easy to generate the code for embedding google photos. Other image hosting sites make it a little easier by offering you the embed code directly, but unfortunately google doesn't, so this website can help generate that code.
Basically, you select your picture, click the share link, then "get link", then copy the link and paste it into the website above, where it will generate the code that you can use to paste into the forum.
Here's an example, a google created animation from the pictures I took at 3 Creeks
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