File Handling Issues in SQL Server

For access denied issues when reading files in SQL Server, the service of SQL Server needs to have rights to the folder.
The user that should be searched:
NT SERVICE\MSSQLSERVER
Source:
https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/configure-file-system-permissions-for-database-engine-access?view=sql-server-2017