请教linux下双显示器的配置问题

我用matlab的PTB的函数XOrgConfSelector时，报错
》XOrgConfSelector
You can choose from the following X11 configuration files:

1. 90-ptbconfig_1_xscreens_1_outputs_modesetting.conf
2. 90-ptbconfig_2_xscreens_2_outputs_modesetting.conf

Which one should i use? (Choose 0 for remove the current active file): 2

Error using copyfile
Cannot write to destination: /etc/X11/xorg.conf.d. Use the 'f' option to override.

Error in XOrgConfSelector (line 56)
copyfile([sdir conffiles{answer}], '/etc/X11/xorg.conf.d/90-ptbxorg.conf');