How to do posterior predictive checks for survival model in interval censorship status?

Dear all,
I want to evaluate my survival model with posterior predictive checks in RSTAN.
For this purpose, I wrote the codes for generating y_rep in the log-logistic model with right-censored data as follows:
‘’’
{real u;
u=uniform_rng(0,1);
for (n in 1:N_uncensored){
y_rep[n] = ((u / (1 - u)) ^ (1 / alpha)) * ((1 / (exp ((-respon_uncensored[n,7:18] * beta - w1[county_uncensored[n]] - theta[county_uncensored[n]]) * alpha))) ^ (1 / alpha));}
}
‘’’.

But I have a problem with writing the codes to evaluate the survival model in interval censorship status. My question is how to generate the y_rep for evaluating the log-logistic survival model with interval-censored data?
Any idea will be greatly appreciated. Thank you in advance!

Regards,
Eisa

Can anyone help me with my problem?

Any suggestions will be greatly appreciated. Thank you in advance!

Warm Regards,
Eisa