Post ID export is a CSV file, meaning this is a delimited text file that uses a comma to separate values. Import the file to any program that stores data in tables, such as Microsoft Excel or Numbers for Mac.
Let's import the file to Google Sheets:
Open an empty sheet
Upload your post ID export – File > Import > Upload
Select the column with post IDs, then click Format > Number > More formats > Custom number format
Apply this format: