Keep healthy or keep healthy?

Both will do.

Health protection usually refers to the provision of health insurance, medical care, disease prevention, living environment sanitation and so on. For example, the government, insurance companies, medical institutions and environmental protection organizations can provide health protection services.

And ensuring health usually refers to the individual's own behavior and lifestyle, while ensuring good health, avoiding any possible harmful factors. For example, exercise more, eat properly, relax and avoid contact with harmful substances.