opam install ocaml-canvas [ERROR] No package named ocaml-canvas found

I want to install the library ocaml-canvas for OCaml.I tried

opam install ocaml-canvas

but the error message is then

$ opam install ocaml-canvas[ERROR] No package named ocaml-canvas found.

I tried then to follow this tutorial and to build the library from the sources. So I downloaded the sources from here.I unzipped , went to the directory and

dune build

gives then these errors:

$ dune buildFile "src/discover/dune", line 5, characters 7-15:5 |  (name discover)           ^^^^^^^^** Fatal error: Cannot find file "-lws2_32"File "caml_startup", line 1:Error: Error during linkingFile "examples/make_index/dune", line 3, characters 7-17:3 |  (name make_index)           ^^^^^^^^^^** Fatal error: Cannot find file "-lws2_32"File "caml_startup", line 1:Error: Error during linkingFile "examples/make_index/dune", line 3, characters 7-17:3 |  (name make_index)           ^^^^^^^^^^** Fatal error: Cannot find file "-lws2_32"File "_none_", line 1:Error: Error while building custom runtime system

So what can I do?