Error, you don't have necessary permissions when creating a form entry mapped to a company scoped object as Guest

Issue

• We have a custom object definition "myobject" that it's mapped to a form.
• When submitting a form entry with a guest user. It shows an error telling that the user doesn't have permissions.

Environment

• Liferay DXP 7.4

Resolution

• Go to the object definition "myobject" and check the value of "Panel Category Key". Per example "Custom Apps"
• Go to control panel -> Roles -> Guest -> Define Permissions
• Look for "Custom Apps" and click in "myobject"
• Add "Add object entry" permission and save.
• After that, you can create new form entries as Guest.