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Does the remote control open and close?
If so, the key is no longer synchronised with the vehicle.
In this case please look in the area of the steering column where the ignition lock used to be. Depending on the model, you will see a cover (round). This can be pulled off, then a shaft appears. Insert the key into this shaft and press the start button. The car now reads the key manually and the car should start.
If the cover is not there, hold the key in place while pressing the start button.
If this does not help, the cause is somewhere else, then unfortunately a garage has to take over the troubleshooting, because there is nothing else you can do.
If the key cannot be unlocked with the FOB, then try to start as described above. If this works, the key has to be checked by Ford, maybe it has an electrical defect.