kotlin
can I somehow create if not exist external file application.properties on start of a jar with default property’s from inner default file

I was given a task to learn how to configure spring boot applications as a jar
Options I came across are creating sub endpoint for the configuration of already active project and external application.properties filebought options seem good but lack benefits of each other. For example, endpoint configuration cannot configure ports and for application.properties to change smf I have to restart application
For my application build project should be in one jar file and any external files, like application.properties should be generated by jar file.

Can I somehow, at the start of an application, check if the file application.properties exists in the current directory and, if not, create it with parameters from the internal application.properties