How to block, mark as spam, or unblock phone numbers on Cubot devices

Cubot P40 Cubot P40
Cubot Note 9 Cubot Note 9
Cubot Max 3 Cubot Max 3
Cubot KINGKONG 5 Cubot KINGKONG 5
Cubot KingKong Mini 2 Cubot KingKong Mini 2
Cubot X30 Cubot X30
Cubot Note 20 Pro Cubot Note 20 Pro
Cubot X19 Cubot X19
Cubot R15 Cubot R15
Cubot Max 2 Cubot Max 2
Cubot Quest Lite Cubot Quest Lite
Cubot J5 Cubot J5
Cubot J7 Cubot J7
Cubot Rainbow 2 Cubot Rainbow 2
Cubot R9 Cubot R9
Cubot Magic Cubot Magic
Cubot Note Plus Cubot Note Plus
Cubot X18 Cubot X18
Cubot H3 Cubot H3
Cubot King Kong Cubot King Kong