How to work with WCCP v2?

When you mean it does not work have you done packet capture on the F5 after following article https://techdocs.f5.com/kb/en-us/products/big-ip_apm/manuals/product/apm-secure-web-gateway-13-1-0/3.html to see if the traffic is reaching the F5 device first and if F5 is returning a reply? You need to do a little investigation:

https://support.f5.com/csp/article/K13637

After that you need to set the SWG as a transperant proxy as if it was explicit you wouldn't need WCCP in the first place:

https://techdocs.f5.com/kb/en-us/products/big-ip_apm/manuals/product/apm-secure-web-gateway-13-1-0/3.html

Extra Article for another F5 module but it is the same for APM:

https://techdocs.f5.com/kb/en-us/products/big-ip-aam/manuals/product/aam-network-configuration-11-6-0/7.html