Total Amount From Various DFF

Good day, experts

I've created DORs using several DFF attributes, such as:

To be clear, each of the attributes below is a number data type:

• Exam Fees [e.g. 500]
• Membership Fees [e.g. 300]
• Reserved Space Fees [e.g. 800]
• Various Fees [e.g. 130]

Since I already have the aforementioned attributes, I would like to combine them into a new attribute called Total Fees [e.g. 1730] Attribute.

For the Total Fees, I want it to be auto calculate, the employee will enter the above attributes only and the system will take care of the Total Fees.

I appreciate your help and advice to know that the aforementioned scenario can be accomplished via Autocomplete or another method.