Below is the link to the fillable form. It can be downloaded, signed and sent back. On the web page the signature field will be disabled. To be able to sign it on the web, you will need an Adobe Sign account. This can be done by using web forms instead of PDF forms.
Recuring Payment Authorization Form
In general, in order to collect sensitive data, especially credit card information, you must use compliant software i.e. payment/document/form processing system or accounting software.
Below is the form as file view. Fillable fields won’t work.