Adding a signature field in latest version of Adobe Acrobat Pro DC

[Jean5E19]

Hello, my co worker recently got the latest version of Adobe Acrobat Pro DC and we can not figure out how to add digital signature fields in her documents. Here is a screen shot of the icons that she has now:

When she clicks on the signature field and places the box where she wants it, it does not prompt you to sign and is acting as just a regular text box field to type in. Does anyone know how she resloves this issue? 

[Bernd Alheit]

Read this:

https://community.adobe.com/t5/acrobat/certificate-based-signature-field/td-p/10323268