Your second example is not valid json. It is jsonl:

JSONL is a text-based format that uses the .jsonl file extension and is essentially the same as JSON format except that newline characters are used to delimit JSON data. It also goes by the name JSON Lines.

To deal with files like this you can read in each line as json, and then rbind() the results. A base R approach (requires at least R 4.2 for the _ placeholder):

library(jsonlite)
json_text <- readLines("tech.json", warn = FALSE, encoding = "UTF-8")

lapply(json_text, fromJSON) |>
    do.call(rbind, args = _) |>
    data.frame()

#   id   name  color price
# 1  1  Apple    red  0.99
# 2  2 Banana yellow   0.5
# 3  3 Orange orange  0.75

Alternatively, here's a dplyr approach:

library(dplyr)
lapply(json_text, fromJSON) |>
    bind_rows()

# # A tibble: 3 x 4
#      id name   color  price
#   <int> <chr>  <chr>  <dbl>
# 1     1 Apple  red     0.99
# 2     2 Banana yellow  0.5 
# 3     3 Orange orange  0.75

And for the sake of completeness here's the data.table way to do the same:

library(data.table)
lapply(json_text, fromJSON) |>
    rbindlist()
#       id   name  color price
#    <int> <char> <char> <num>
# 1:     1  Apple    red  0.99
# 2:     2 Banana yellow  0.50
# 3:     3 Orange orange  0.75