MLT-BT05 CAN'T CHANGE PIN AND TYPE

Hi, I have MLT-BT05 version 4.45. I am inputting AT commands through the serial monitor. When I type

"AT", it respond "OK",
"AT+NAME=HELPME", it respond "OK"
"AT+PIN", it respond "+PIN=123456"
"AT+TYPE", it respond "+TYPE=0"

But when I change the pin and type,

"AT+PIN=888888", it respond "ERR"
"AT+PIN='888888' ", it respond "ERR"
"AT+PIN="888888" ", it respond "ERR"

"AT+TYPE=2", no respond
"AT+TYPE='2' ", no respond
"AT+TYPE="2" ", no respond

Can someone help me? I want to change the type and pin but it errored

According to the documentation (which you failed to provide a link to!) you have to omit the equal sign ("=") in the set command.

So

AT+PIN888888

should set the PIN to 888888.

Sorry for not giving the link for documentation I didnt find any datasheet for v4.45. Thanks you so much It works!