How to create folders on SharePoint 2019 using REST calls via postman? Getting 403: Forbidden error - rest

Question

I am using the below call to create a folder on SharePoint2019:
POST http://<site>/_api/web/folders
{
"__metadata": {
"type": "SP.Folder"
},
"ServerRelativeUrl": "/Shared Documents/Folder"
}
But I am getting the following error:
403 Forbidden: The security validation for this page is invalid and might be corrupted. Please use your web browser's Back button to try your operation again.

Answer 1

Please check if you have got the valid form digest value in your side.
For example, if the site url is http://sp/sites/dev/
Then do a Post Request to this url http://sp/sites/dev/_api/contextinfo
Then use this form digest value in Request Header:
Here is a sample request to create folder using Rest:
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>
<script>
$(function () {
bindButtonClick();
});
function bindButtonClick() {
$("#btnSubmit").on("click", function () {
createFolder();
});
}
function createFolder() {
var folderName = $("#txtFolderName").val();
var siteUrl = _spPageContextInfo.webAbsoluteUrl;
var fullUrl = siteUrl + "/_api/web/folders";
$.ajax({
url: fullUrl,
type: "POST",
data: JSON.stringify({
'__metadata': { 'type': 'SP.Folder' },
'ServerRelativeUrl': 'Shared Documents/' + folderName
}),
headers: {
"accept": "application/json;odata=verbose",
"content-type": "application/json;odata=verbose",
"X-RequestDigest": $("#__REQUESTDIGEST").val()
},
success: onQuerySucceeded,
error: onQueryFailed
});
}
function onQuerySucceeded() {
$("#divResults").html("Folder created successfully !!!");
}
function onQueryFailed() {
alert('Error!');
}
</script>
<div>
<strong>Enter FolderName:</strong><br />
<input type="text" id="txtFolderName" /><br />
<input type="button" id="btnSubmit" value="Create Folder" />
</div>
<div id="divResults"></div>
Reference:
Some Help for Authorization Problems in SharePoint 2013 REST API