'pulseOxymeter_t' was not declared in this scope

Arduino: 1.8.13 (Windows 10), Board: "LOLIN(WEMOS) D1 R2 & mini, 80 MHz, Flash, Legacy (new can return nullptr), All SSL ciphers (most compatible), 4MB (FS:2MB OTA:~1019KB), v2 Lower Memory, Disabled, None, Only Sketch, 115200"

In file included from C:\Users\ASUS\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkApi.h:17:0,

from C:\Users\ASUS\Documents\Arduino\libraries\Blynk\src/BlynkApiArduino.h:14,

from C:\Users\ASUS\Documents\Arduino\libraries\Blynk\src/BlynkSimpleEsp8266.h:24,

from C:\Users\ASUS\Documents\Arduino\esp_8266\esp_8266.ino:7:

C:\Users\ASUS\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkTimer.h:36:21: error: redefinition of 'class BlynkTimer'

#define SimpleTimer BlynkTimer

^

C:\Users\ASUS\Documents\Arduino\libraries\SimpleTimer/SimpleTimer.h:10:7: note: in expansion of macro 'SimpleTimer'

class SimpleTimer {

^

C:\Users\ASUS\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkTimer.h:36:21: error: previous definition of 'class BlynkTimer'

#define SimpleTimer BlynkTimer

^

C:\Users\ASUS\Documents\Arduino\libraries\Blynk\src/Blynk/BlynkTimer.h:41:7: note: in expansion of macro 'SimpleTimer'

class SimpleTimer {

^

C:\Users\ASUS\Documents\Arduino\esp_8266\esp_8266.ino: In function 'void loop()':

esp_8266:46:1: error: 'pulseOxymeter_t' was not declared in this scope

pulseOxymeter_t result = pulseOxymeter->update();

^

esp_8266:46:17: error: expected ';' before 'result'

pulseOxymeter_t result = pulseOxymeter->update();

^

esp_8266:48:5: error: 'result' was not declared in this scope

if( result.pulseDetected == true )

^

exit status 1

'pulseOxymeter_t' was not declared in this scope

This report would have more information with
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can you help me about that? thannks

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My guess would be that the library that defines 'pulseOxymeter_t' is not included in your sketch.