Finding the Sum and Count to make a percentage for groups

General
2

With your data:

library(tidyverse)
df <- tibble::tribble(
              ~gender, ~last_quantitative_lab_value, ~viral_suppression_numeric,
               "Male",                          20L,                         0L,
               "Male",                          20L,                         0L,
               "Male",                          20L,                         0L,
               "Male",                          22L,                         0L,
               "Male",                          20L,                         0L,
             "Female",                          20L,                         0L,
               "Male",                          20L,                         0L,
               "Male",                          20L,                         0L,
        "Transgender",                        1490L,                         1L,
             "Female",                        1000L,                         1L,
               "Male",                          20L,                         0L,
               "Male",                         205L,                         1L,
               "Male",                          20L,                         0L,
               "Male",                          22L,                         0L,
               "Male",                         208L,                         1L,
             "Female",                          20L,                         0L,
             "Female",                         201L,                         1L,
             "Female",                         207L,                         1L,
        "Transgender",                          20L,                         0L,
             "Female",                        1000L,                         1L
        )

df %>% 
  group_by(gender) %>% 
  count(viral_suppression_numeric) %>% 
  mutate(prop = n/sum(n))

# A tibble: 6 × 4
# Groups:   gender [3]
  gender      viral_suppression_numeric     n  prop
  <chr>                           <int> <int> <dbl>
1 Female                              0     2 0.333
2 Female                              1     4 0.667
3 Male                                0    10 0.833
4 Male                                1     2 0.167
5 Transgender                         0     1 0.5  
6 Transgender                         1     1 0.5

For making it reproducible next time: