Sonarqube error : The main branch of this project is empty

Hello,
Today I installed sonarqube and sonarqube runner to scan my php project . But after running the scanner it shows The main branch of this project is empty. .

sonar-scanner.properties

#Configure here general information about the environment, such as SonarQube server connection details for example
#No information about specific project should appear here

#----- Default SonarQube server
#sonar.host.url=http://localhost:9000

#----- Default source code encoding
#sonar.sourceEncoding=UTF-8


sonar.projectKey=raka
# --- optional properties ---

# defaults to project key
#sonar.projectName=My project
# defaults to 'not provided'
#sonar.projectVersion=1.0
 
# Path is relative to the sonar-project.properties file. Defaults to .
#sonar.sources=.
 
# Encoding of the source code. Default is default system encoding
#sonar.sourceEncoding=UTF-8

Can anyone tell me what am I doing wrong ? I want to test my php application using sonarqube

EDIT
I just found this warning
SCM provider autodetection failed. Please use “sonar.scm.provider” to define SCM of your project, or disable the SCM Sensor in the project settings.

Hello,
Could you please post your scanner logs?