Connecting LMHOME 008

Dear all,

I'm looking for a way to point my GPS tracker to Traccar. It's a Chinese clone, sold on Amazon (.ca, .co.uk, .de) and AliExpress as 'LMHOME 008 Mini', 'LMHOME Mini' or 'LM008'. Manufacturer is mentioned as 'Yangtongjixies', 'minkoo' or 'Haoday'. Physically it's a grey 47x23x18mm 23g block with a nano SIM GPRS modem and a 650mAh battery. Default platform is available on the web (www.gps903.net) and Android/iOS (GPSONE app). So far it accepted the following SMS commands (123456 is the default password):

admin123456 [new admin phone number]
apn123456 [APN name]
begin123456
check123456
gprs123456
lowbatsms123456 [on/off]
noadmin123456 [existing admin phone number]
password123456 [new password]
timezone123456 [UTC offset in hours]

'Check' replies with the following:

HL392_VER_1.0.15,ID:[unique 10-digit device ID],
IP:b.gps903.net:7700,
APN:[APN name],
UP:[reporting interval in seconds],GPS:[number of connected GPS satellites?],GSM:[positive number - RSSI?],
[admin phone number 1 or *],[admin phone number 2 or *],[admin phone number 3 or *],[admin phone number 4 or *]

Provided manual and seller's websites do not mention a way to connect the tracker to another server. IP:b.gps903.net:7700 hints at that being possible, but I've failed to find the correct command. Some that I tried:

adminip123456 [ip] [port]
SERVER,123456,[ip],[password]#
SZCS,123456,DOMAIN=[ip]:[port]
IP [ip] [port]
IP#[ip]#[port]#
IP1,[ip],[port]

Any advice would be appreciated. I plan to eventually switch to an LTE-M device, but for the moment am unfortunately stuck with this one and connecting it to Traccar would really help.