When Simulation window is opened, you can type "plot" command and the node that you want to plot. For eg: plot v(2). And you also check your Ngspice Netlist in your project folder, whether there is plot command in your netlist.
<span style="line-height: 21.4285717010498px;">Let us know if you face any difficulties while using it. </span>
Thank you sir for your reply. Im getting the plot but if i want to plot (example: V(1) vs V(2)) then how should i do it?