Facing an error that an id statement is required for multi-state models while running cox model in R

Question

i am trying to run cox regression model in R studio but facing same error every time.

cox.model <-coxph(Surv(dat$los, dat$died) ~ gender, data=dat)
Error in coxph(Surv(dat$los, dat$died) ~ gender, data = dat) : 
  an id statement is required for multi-state models

Here is data: