ANSI file encoding

My Grafana version is 6.6.0. I have a problem configuring the file ldap.toml. There are Organization Unit (OU) with Russian names in our domain.
If I use ANSI encoding, then Russian characters are replaced with question marks. If I save the file in Unicode encoding, then Grafana does not read it.

How can I solve the problem without renaming the OU?
Is it possible to change the encoding for this file somewhere?

Log with Unicode:
t=2020-10-06T15:25:08-0500 lvl=info msg=“LDAP enabled, reading config file” logger=ldap file=“C:\Program Files\GrafanaLabs\grafana\conf\ldap.toml”
t=2020-10-06T15:25:08-0500 lvl=eror msg=“Failed to obtain the LDAP configuration. Please verify the configuration and try again” logger=context userId=1 orgId=4 uname=admin error=“Failed to load LDAP config file: Near line 0 (last key parsed ‘’): bare keys cannot contain ‘�’”

Unicode: group_dn = “CN=Test_OSM,OU=Отдел,OU=Проверка,DC=grafana,DC=local”
ANSI: group_dn = “CN=Test_OSM,OU=???,OU=???,DC=grafana,DC=local”

Tell me please.
Where can I read about file extension in Grafana?

I tried saving the file using “Unicode without signature - codepage 65001”. Worked with German Umlaute (äöü) afterwards.