Signpad Modification Required

I need a freelancer to modify a signpad for me, preferably within the next hour or two.

Requirements:
- When "Save" is clicked:
- Signature is saved on the server
- Alert: "Success and path-to-file" (controlled in main file: form_bull_ride_email_sign.php)

- If stroke length is less than 500:
- Alert instead of success alert
- No image is saved

- Hide the download button

- Ability to change button styling inside form_bull_ride_email_sign.php via CSS or jQuery

Ideal skills and experience:
- Proficiency in JavaScript
- Experience with signature pads and form handling
- Quick turnaround time