Need to fix the wordpress website issues

Description

Hello,
We are a product base company our website is into wordpress we have developed customised theme for our company https://www.productdossier.com.
We need to fix the website issues1. Submit button is not working on request demo page for http://www.productdossier.com2. To resolve Memory leakage in Plesk hosting control panel3. Need to know the cookies from our website http://www.productdossier.com4. Fix CSP(content security policy) issues5. There are more that 150 broken, feed links on google search console that need to fix
Thanks and regards,Prasad Mane