#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)(<p>(?=<img\s.*?))(.*?)(</p>)"
Local $sString = "<p><img src="/files/ffea8817-b5c4-406e-a7b2-3f6e52c69398.png" style="height:901px; width:797px" /></p>" & @CRLF & _
"<p><img src="/files/ffea8817-b5c4-406e-a7b2-3f6e52c69398.png" style="height:901px; width:797px" /></p>" & @CRLF & _
"" & @CRLF & _
"<p><img src="/files/ffea8817-b5c4-406e-a7b2-3f6e52c69398.png" style="height:901px; width:797px" /></p>" & @CRLF & _
"" & @CRLF & _
"<p><img src="/files/ffea8817-b5c4-406e-a7b2-3f6e52c69398.png" style="height:901px; width:797px" /></p><p><img src="/files/ffea8817-b5c4-406e-a7b2-3f6e52c69398.png" style="height:901px; width:797px" /></p>" & @CRLF & _
""
Local $sSubst = "<figure class="image">\2</figure>"
Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst)
MsgBox($MB_SYSTEMMODAL, "Result", $sResult)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm