According to your current description, if the unit proposes, it is necessary to pay liquidated damages.

Unless otherwise agreed, the amount of liquidated damages = training fee divided by 5 years multiplied by (5 years minus the time after training).

Please refer to Article 22 of the Labor Contract Law: If an employer provides special training fees for its employees and provides them with professional and technical training, it may conclude an agreement with the employees to stipulate the service period. If the laborer violates the service period agreement, he shall pay liquidated damages to the employer in accordance with the agreement. The amount of liquidated damages shall not exceed the training expenses provided by the employer. The liquidated damages that the employer requires the laborer to pay shall not exceed the training expenses that should be shared for the unfinished part of the service period.