We can read yaml file within Runspace using code given in below post 
How to read remote yaml file present in Azure VM from local machine using C# Runspace
But how to update existing remotely located yaml file.
I want to use code using YamlDotnet similar to one given in below post to create some new data to be updated into existing yaml file.
Build a Yaml document dynamically from c#
Update:
I have inventory yaml file with its contents as below
targets:
      - uri: 80.587.459.478
        config:
             transport: ssh
             ssh:
                 user: testlinuxuname
                 private-key: ~/ssh-key/SSH-PrivateKey.txt
                 host-key-check: false
                 run-as: root
      - uri: targetwindows123
        config:
             transport: winrm
             winrm:
                  user: testusername
                  password: testpwd
                  ssl-verify: false
Yaml file is located in remote Azure VM.
Requirement: I want to read
yamlfile which is present in remote azure vm fromC#and check if particularurivalue exists or not. If particularurivalue doesn't exist, then I need to append newuridata toyamlfile. So new record will be appended next to existing data inyamlfile.New record will be something like below.
- uri: targetwindows567 config: transport: winrm winrm: user: testusername1 password: testpwd1 ssl-verify: falseI want to check if
urivaluetargetwindows567exists or not inyamlfile. If it don't exist, then add above records into the remoteyamlfile.
 
    