Hi!
Thanks for reaching out to us. To achieve a better user experience, Huawei decided to completely terminate the unlock code application service on July 25th, 2018 and published the relevant announcement on the EMUI official website in May 2018. We are sincerely sorry for the possible inconvenience.
Here is the Enterprise forum. You may find more professional answers on the Consumer website:
https://consumer.huawei.com/en/.
You could also send an email to mobile@mail01.huawei.com or dial the hotline number (https://consumer.huawei.com/en/support/hotline/) to obtain technical support.