Is the phone rooted? AFAIK, Android Go is determined by the value of ro.config.low_ram in build.prop. (Ref: Disable Android Go?)

Hmm, I guess I read the question differently. I thought it's about account used for the installation, not for the in-app registration...

Related: How do I factory reset this Chinese device? (but looks like the menu is slightly different and thus the answer doesn't apply)

Possible dupe? How Do I Know Which Google Account is Used for the Market?

Community bump prevention: this question was closed because the question seems to have been abandoned (OP hasn't visited the network for more than 5 years, and no answers have score above 0). If anyone can evaluate the existing answers, feel free to vote accordingly and reopen the question (or mod-flag the question requesting for reopening). For anyone else having the same issue, please post a new question and refer to this question as additional context.

Sorry, this question is off-topic because KaiOS doesn't seem to be based on Android but Linux. Unix & Linux might be more suitable for this.