Create proxy with Raspberry PI and multiple Huawei E3372h

hi, I would like to create multiple proxies through my Raspberry and huawei e3372h keys. I tried using this guide, but without success: [login to view URL] I need to have the proxy accessible anywhere via username and password and with the ability to rotate the ip whenever I want and use more than one huawei e3372h keys if i want more proxy .