user46901: Here is the code I used to get BPM from pulse sensor.
#define USE_ARDUINO_INTERRUPTS true    // Set-up low-level interrupts for most 
acurate BPM math.
#include <PulseSensorPlayground.h>     // Includes the PulseSensorPlayground 
Library.

//  Variables
const int PULSE_SENSOR_COUNT = 2;
const int PulseWire = A0;
const int PulseWire2 = A1;
const int LED13 = 13;
int Threshold = 550;

void setup() {
  Serial.begin(9600);
  pulseSensor.analogInput(PulseWire, 0);
  pulseSensor.analogInput(PulseWire2, 1);
  pulseSensor.blinkOnPulse(LED13);
  pulseSensor.setThreshold(Threshold);
  if (pulseSensor.begin()) {
  }

  void loop() {
    int myBPM = pulseSensor.getBeatsPerMinute();  // Calls function on our pulseSensor object that returns BPM as an "int".

    if (pulseSensor.sawStartOfBeat()) {            // Constantly test to see if "a beat happened".
      //Serial.println("♥  A HeartBeat Happened ! "); // If test is "true", print a message "a heartbeat happened".
      Serial.print("BPM1: ");                        // Print phrase "BPM: "
      Serial.println(myBPM);                        // Print the value inside of myBPM.
    }
    delay(20);                    // considered best practice in a simple sketch.
  }

I wish to separate display the BPM that get from A0 wire and A1 wire. Serial could print something like this: BPM1(A0):75, BPM2(A1):80.
I don't know how to do that, can anyone help me with it?

user37523: Change "#define USE_ARDUINO_INTERRUPTS true" to "#define USE_ARDUINO_INTERRUPTS false".

If, instead, your Sketch does not use interrupts to read PulseSensor data, your Sketch must instead contain the following two lines, in order:
#define USE_ARDUINO_INTERRUPTS false
#include <PulseSensorPlayground.h>

Source: https://github.com/WorldFamousElectronics/PulseSensorPlayground/blob/master/src/PulseSensorPlayground.h

46901: <p>Here is the code I used to get BPM from pulse sensor.</p>

<pre class="lang-cpp prettyprint-override"><code>#define USE_ARDUINO_INTERRUPTS true    // Set-up low-level interrupts for most 
acurate BPM math.
#include &lt;PulseSensorPlayground.h&gt;     // Includes the PulseSensorPlayground 
Library.
</code></pre>

<p>//  Variables</p>

<pre><code>const int PULSE_SENSOR_COUNT = 2;
const int PulseWire = A0;
const int PulseWire2 = A1;
const int LED13 = 13;
int Threshold = 550;

void setup() {
  Serial.begin(9600);
  pulseSensor.analogInput(PulseWire, 0);
  pulseSensor.analogInput(PulseWire2, 1);
  pulseSensor.blinkOnPulse(LED13);
  pulseSensor.setThreshold(Threshold);
  if (pulseSensor.begin()) {
  }

  void loop() {
    int myBPM = pulseSensor.getBeatsPerMinute();  // Calls function on our pulseSensor object that returns BPM as an "int".

    if (pulseSensor.sawStartOfBeat()) {            // Constantly test to see if "a beat happened".
      //Serial.println("♥  A HeartBeat Happened ! "); // If test is "true", print a message "a heartbeat happened".
      Serial.print("BPM1: ");                        // Print phrase "BPM: "
      Serial.println(myBPM);                        // Print the value inside of myBPM.
    }
    delay(20);                    // considered best practice in a simple sketch.
  }
</code></pre>

<p>I wish to separate display the BPM that get from A0 wire and A1 wire. Serial could print something like this: <code>BPM1(A0):75, BPM2(A1):80</code>.
I don't know how to do that, can anyone help me with it?</p>
 37523: <p>Change &quot;#define USE_ARDUINO_INTERRUPTS <strong>true</strong>&quot; to &quot;#define USE_ARDUINO_INTERRUPTS <strong>false</strong>&quot;.</p>
<blockquote>
<p>If, instead, your Sketch does not use interrupts to read PulseSensor data, your Sketch must instead contain the following two lines, in order:</p>
<p>#define USE_ARDUINO_INTERRUPTS false</p>
<p>#include &lt;PulseSensorPlayground.h&gt;</p>
</blockquote>
<p>Source: <a href="https://github.com/WorldFamousElectronics/PulseSensorPlayground/blob/master/src/PulseSensorPlayground.h" rel="nofollow noreferrer">https://github.com/WorldFamousElectronics/PulseSensorPlayground/blob/master/src/PulseSensorPlayground.h</a></p>
