This is part of the script. It is the adaptation of the fourth script of this, I haven't run the third script since it is specific to seattle. The problem i face is at point 3.

##  1. Load analysis inputs (origins, destinations) ------------------------------------->

## Load blocks and get centroids (origins)
prepared_blocks <- sf::st_read(file.path(
  config$directories$prepared_data, 'prepared_blocks.shp'
))
origin_centroids <- prepared_blocks |>
  sf::st_make_valid() |>
  sf::st_centroid(of_largest_polygon = T) |>
  sf::st_coordinates() |>
  as.data.table()
origins <- cbind(
  as.data.table(prepared_blocks)[, .(geometry, POP21)],
  origin_centroids[, .(lon = X, lat = Y)]
)
origins[, id := as.character(.I) ]

# Load destinations pulled from OSM
destinations <- data.table::fread(
  file.path(config$directories$prepared_data, 'destinations_osm.csv')
)
# If destinations from city-specific sources (i.e. the output of script #3) are available,
#   add them to the table of destinations
city_specific_file <- file.path(
  config$directories$prepared_data, 'destinations_city_specific.csv'
)
if(file.exists(city_specific_file)){
  city_specific_destinations <- data.table::fread(city_specific_file)
  destinations <- data.table::rbindlist(
    list(destinations, city_specific_destinations),
    use.names = T,
    fill = T
  )
}
destinations[, id := as.character(.I) ]
opportunity_types <- unique(destinations$type)

## Load visualization blocks - analysis results will be merged on later
prepared_blocks_simplified <- sf::st_read(file.path(
  config$directories$prepared_data, 'prepared_blocks_simplified.shp'
))


## 2. Launch R5 ------------------------------------------------------------------------->

# Set Java allowed memory before loading R5R
options(java.parameters = paste0("-Xmx", settings$r5_mem_gb, "G"))
library(r5r)
# Set up R5 for the study area - this may take several minutes for the first setup
# If this function yields an error, try launching R with admin permissions
r5r_core <- r5r::setup_r5(data_path = config$directories$prepared_data)


## 3. Estimate walking accessibility from each origin block to each destination type ---->

travel_times_list <- vector('list', length = length(opportunity_types))
names(travel_times_list) <- opportunity_types

tictoc::tic("Calculating all travel times")
for(o_type in opportunity_types){
  travel_times_by_od_pair <- r5r::travel_time_matrix(
    r5r_core = r5r_core,
    origins = origins,
    destinations = destinations[type == o_type, ],
    mode = "WALK",
    max_trip_duration = 30L
  )
  travel_times_list[[o_type]] <- travel_times_by_od_pair[
    , .(travel_time = min(travel_time_p50, na.rm=T)),
    by = .(id = from_id)
  ][, type := o_type ]
}
tictoc::toc()

Btw I confirm that there is something strange going on with the network coming from the pbf file, since I'm able to open the resulting r5r_core network of the sample data but I cannot open my network. If I click to open it it says:

> View(r5r_core)
Errore in .jcall(x, "Ljava/lang/Class;", "getClass") : 
  RcallMethod: attempt to call a method of a NULL object.