Accumulated depreciation

Is it possible to add the custom option field to Accumulated depreciation, thanks!

I don’t think so but you can add them to a Fixed Asset.

What are you trying to achieve?

Custom fields can only be created for transactions and subsidiary ledgers. Fixed assets, accumulated depreciation is an account. So, in the same way that you can add a custom field for a customer but not for Accounts receivable, you can add one for a fixed asset but not for Fixed assets, accumulated depreciation.