I have  a Microservice written in python flask and I will be hosting it soon.
I want to send one file (example.txt) to My Microservice as a part of Bamboo Task. 
The  microservice will use this file and extract some useful information.
The bamboo is connected with Bitbucket.
Questions:

How do I achieve this in Bamboo?
Are there any changes required at my Micreservice.

I newbie in all these technologies. Any help is appreciated.
There are few steps to acheive this.

Setting up the microservice to accept file.
Make sure your micro-service is able to accept the file. If yes, perfect. Then we only need to work on the below steps.
Extracting the file from the build plan. 
Create the build plan and add the build task, this task should produce your artifact file "example.txt", You need to choose the build task which is suitable for your mircoservice client project(Node, maven). The artifact cannot be persisted if you don't mark it as a shared artifact. Describe the shared artifact in task settings. The artifact is shown when the build completes that would confirm that the build is working properly and producing the required artifact.
Sending the file from a deployment plan.
Once the artifact is available. You need to create the deployment plan, which can be a script in python or bash to do a REST call for transferring the file. Make sure the location of the file is correct in the script.
How to send a file from Bamboo task to a our python Microservice