build error for dart version

Docker Error: The current Dart SDK version is 2.16.2.

Because open_runtimes_dart depends on appwrite_function from path which requires SDK version >=2.17.0 <3.0.0, version solving failed.
Resolving dependencies...

• collection 1.17.0 (1.17.2 available)
• matcher 0.12.12 (0.12.16 available)
• meta 1.9.1
• path 1.8.3
• pub_semver 2.1.2 (2.1.4 available)
• pubspec 2.3.0
• quiver 3.1.0 (3.2.1 available)
• source_span 1.9.1 (1.10.0 available)
• stack_trace 1.10.0 (1.11.0 available)
• string_scanner 1.1.1 (1.2.0 available)
• term_glyph 1.2.1
• uri 1.0.0
• yaml 3.1.1 (3.1.2 available)
  Downloading pubspec 2.3.0...
  Downloading uri 1.0.0...
  Downloading yaml 3.1.1...
  Downloading string_scanner 1.1.1...
  Downloading path 1.8.3...
  Downloading quiver 3.1.0...
  Downloading collection 1.17.0...
  Downloading pub_semver 2.1.2...
  Downloading source_span 1.9.1...
  Downloading term_glyph 1.2.1...
  Downloading matcher 0.12.12...
  Downloading stack_trace 1.10.0...
  Downloading meta 1.9.1...
  Changed 13 dependencies!
  found user package appwrite_function
  added user package as dependency to server.
  Updated server import of user code
  Resolving dependencies...

this error is coming when i try to build my function

You need to upgrade your code.

I highly recommend using the CLI to initialize your function code as the docs suggest: https://appwrite.io/docs/functions#gettingStarted

Then, you can update it to do what you want.