You can use the 'pdftk' command-line tool to merge your PDF files. Here is an example to run this command:
pdftk file1.pdf file2.pdf cat output new_merged_file.pdf
In the above command, file1.pdf and file2.pdf are input files that you want to merge, and new_merged_file.pdf is the merged file. Replace these file names with your file names.
If pdftk is not installed, you can install it using one of the following commands:
sudo snap install pdftk
sudo apt install pdftk
