Did you sign up or login to the Huawei account?
You need that I suppose
Update! A bit long winded, so pls bear with me.
Called the Huawei Hotline last evening to enquire about the theme app issues. Was told that theme app should work normally with downloadable themes. Asked me to go to the service centre @ 313. So today i went down to Huawei Service Centre.
When i was there, the counter staff told me that it should work and show me the huawei test set that the app is indeed working and filled with lots of downloadable themes. She requested to reboot my phone and i had to wait for almost 2 hours for it.
Upon collection, the problem wasn't resolved! and another technician came to access the phone. After meddling with the phone, He then informed me that Local Mate10 set was software blocked to receive themes from the app! I was shocked to hear that and asked him why the test set and my mate9 (brought it with me) are able to do it. He was equally stunned and started to talk nonsenses like... my mate9 is export set! (singtel set) and the Huawei test set is for testing only. Also he claimed all local xiaomi phones also are blocked to download themes. I gave up soon after i know he is just finding excuses and he is totally clueless. However he did tell me that he will investigate and get back to me. At that point of time, i was already utterly disappointed with Huawei SC.
So in conclusion, Local set (mate10 or pro) cannot download customize themes from the reloaded theme app. Thanks for reading.