Hi Teaksato
Hope you are doing well and sorry for the trouble. As described your client wants to add an initial field instead of the signature field.
- Is he trying to add the initial field while creating the PDF form or when sending the form for signature?
- What is the workflow/steps you are doing?
If you are trying to add the initial fiels when creating the PDF form, please try the following steps:
Go to Tools > Prepare form and Select 'This document require signature' and click 'Start' and then you will get the option to insert the initial field in the PDF Form as shown below:

For more information please check the help page: https://helpx.adobe.com/acrobat/using/creating-distributing-pdf-forms.html#Sign_forms
If you are trying to add initial field when sending the PDF form for signature via Adobe Sign , please check the help page listed below:
- https://helpx.adobe.com/acrobat/using/send-for-signature.html#Continuous
- https://helpx.adobe.com/sign/how-to/adobe-adding-form-fields.html
Hope this information will help
Regards
Amal