"Token type is not allowed" error on sharepoint REST API

Question

Aim:- To access sharepoint through REST Api

Steps taken:-

Created site on sharepoint.
Registered site as an app using https://<<domain>>/sites/<<site name>>/_layouts/15/appregnew.aspx
Granted tenant scope permission using https://<<domain>>/sites/<<site name>>/_layouts/15/appinv.aspx
Permission xml used
<AppPermissionRequests AllowAppOnlyPolicy="true">
<AppPermissionRequest Scope="http://sharepoint/content/sitecollection/web" Right="FullControl" />
</AppPermissionRequests>
4. Collected app identifier from https://<<domain>>/sites/<<site name>>/_layouts/15/appprincipals.aspx
5. Fetched access token using https://accounts.accesscontrol.windows.net/\<<tenant id>>/tokens/OAuth/2/
6. Tried to search using https://bhyve10.sharepoint.com/sites/Tech/\_api/search/query?querytext='smart'
Headers
Content-Type:application/json;odata=verbose
Accept:application/json;odata=verbose
Authorization:Bearer <<access token from step 5>>

     Got below error message
      {"error":"invalid_request","error_description":"Token type is not allowed."}

Answer 1

Hi @Aniket Nade ,
For new SharePoint subscription Grant App Permission is disabled by default or the browser link https://xxxx-admin.sharepoint.com/_layouts/15/appinv.aspx is disabled. To enable this feature, we need to connect to SharePoint using Windows PowerShell and then run set-spotenant -DisableCustomAppAuthentication $false.

Install-Module -Name Microsoft.Online.SharePoint.PowerShell  
$adminUPN="<the full email address of a SharePoint administrator account, example: ******@contosotoycompany.onmicrosoft.com>"  
$orgName="<name of your Office 365 organization, example: contosotoycompany>"  
$userCredential = Get-Credential -UserName $adminUPN -Message "Type the password."  
Connect-SPOService -Url https://$orgName-admin.sharepoint.com -Credential $userCredential  
set-spotenant -DisableCustomAppAuthentication $false  

Afterward, run https://<<domain>>/sites/<<site name>>/_layouts/15/appinv.aspx to grant permission

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

---

Answer 2

Any other way to solve this issue? I don't have admin access neither I can get it.