Simply get a vector of names of all LAS files (*.las, *.laz, *.laz.copc) in the folder.
Examples
f <- system.file("extdata", package = "managelidar")
get_names(f)
#> [1] "3dm_32_547_5724_1_ni_20240327.laz" "3dm_32_547_5725_1_ni_20240327.laz"
#> [3] "3dm_32_548_5724_1_ni_20240327.laz" "3dm_32_548_5725_1_ni_20240327.laz"