Firmware downgrade

I would like to downgrade my firmware to a version lower than this & would like to know how to access the CLI. Thanks.

Current firmware version - QC50Q_H510YTL_1.0.24_301

Which Quectel product you are using now?
QC50Q_H510YTL_1.0.24_301 seems not the Quectel modem.

The modem is using RG500Q-EA

Please provide the current firmware version.

Model is RG500Q-EU
But somehow modem firmware shows QC50Q_H510YTL_1.0.24_301
Maybe my provider tries to hide the actual data.

Please povide the IMEI on it.

My IMEI number is 862471060136470

SN: MPY22G410001638
IMEI: 862471060136470

So the firmware version should be RG500QEUAAR12A02M4G

And Please check the link I sent.