library(rstan)
library(rstanarm)
data(wells)
wells$dist100 <- wells$dist / 100

t_prior <- student_t(df = 7, location = 0, scale = 2.5)
fit1 <- stan_glm(switch ~ dist100, data = wells,
                 family = binomial(link = "logit"),
                 prior = t_prior, prior_intercept = t_prior,
                  seed = 12345)
print(fit1)