How to get FFT coefficient plot

How to obtain FFT for the given amplitude (vs) time plot?

Kindly inform me is below code is right ?? as I don'see any FFT peaks in the figure 2?

clear all

close all

% 200 kHz frequency load and the length of time signal is till 10761 as shown

figure

% provides time(vs) amplitude values

E = load ('5200D1218');

%Fs = 200*10^3; %frequency load used 200kHz

T = E.data(1,1).vectorza(1,1:10761); % time

P = E.data(1,1).Amplitude(4,1:10761); % amplitude values obtained

plot(T,P);

%now to plot FFT for the amp(vs) time results

figure

p = fft(P);

plot(T,p);

Answer 1

[Satoshi Kobayashi]

figure
p = fft(P);
plot(T,abs(p)/length(p)); % two-sided spectrum

[Ramesh Bala]

Danke

I will give a try ,but what is the length ?? is that the last value of the amplitude of the signal

[Satoshi Kobayashi]

That is signal length.

I refered to

https://mathworks.com/help/matlab/ref/fft.html