1. Click on "Settings."
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2. Click on "Custom Fields".

3. Click on "Add Field".

4. Click on "File Upload".

5. Review the preview section.
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6. After that, click "Next" to proceed.

7. Enter a name in the "Field Name" section.

8. Use the drop-down menu to select a "Group."

9. Another drop-down menu will appear for object selection.

10. Check the box of the type of file you want to upload.

11. Click on "Additional Preferences" for further customization.
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12. If you require a unique key, click to customize it.

13. Add description of the field.

14. As the last step, click on "Save".
