You can input current from the terminal AM of the inverter to the programmable controller (for A/D conversion) and control the speed with the software of the programmable controller.
In this case, since the response from the terminal AM is slightly slow (several hundreds ms), you need to determine if this delay does not cause a problem in case when fast-response is required.
If you do not need to control the speed in an analog way but just need to simply lower the speed when current exceeds a certain level, it is recommended to use Pr.150 to Pr.153 (Output current detection level and Zero current detection level).
Since the zero current detection level can be set to 200%, using both parameters allows for two-stage control.