#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = ",, | , |,"
Local $sString = "For the business trip to Germany please don't forget to bring your passport, credit card,, invitation letter , travel adapter,charging cables and enough clothes."
Local $sSubst = ", "
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