Does Folder Exist
Check to see if a folder exists and store the result (TRUE/FALSE) in a designated variable.
When adding a 'Does folder exist' command, you have the option to select either the Local File System or SharePoint Online as the file storage location.
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Select Local File System as your file storage location.
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Enter the full path of the folder you wish to check.
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Enter the name of the variable where you would like to store the result of the check. The result will be either TRUE or FALSE, depending on the outcome.
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You can verify the existence of a folder in your SharePoint Online.
See here for details, SharePoint Online.