npm problem

ah@debian9:~$ npm install --global pure-prompt
npm WARN lifecycle The node binary used for scripts is /snap/bin/node but npm is using /snap/node/1627/bin/node itself. Use the `--scripts-prepend-node-path` option to include the path for the node binary npm was executedwith.

> pure-prompt@1.9.0 postinstall /home/ah/.npm-global/lib/node_modules/pure-prompt
> PURE_DEST=/usr/local/share/zsh/site-functions npm run --silent postinstall-link && exit 0; PURE_DEST="$PWD/functions" npm run postinstall-link && npm run postinstall-fail-instructions

ln: failed to create symbolic link '/usr/local/share/zsh/site-functions/prompt_pure_setup': Permission denied
npm WARN lifecycle The node binary used for scripts is /snap/bin/node but npm is using /snap/node/1627/bin/node itself. Use the `--scripts-prepend-node-path` option to include the path for the node binary npm was executedwith.

> pure-prompt@1.9.0 postinstall-link /home/ah/.npm-global/lib/node_modules/pure-prompt
> mkdir -p "$PURE_DEST" && ln -sf "$PWD/pure.zsh" "$PURE_DEST/prompt_pure_setup" && ln -sf "$PWD/async.zsh" "$PURE_DEST/async"

npm WARN lifecycle The node binary used for scripts is /snap/bin/node but npm is using /snap/node/1627/bin/node itself. Use the `--scripts-prepend-node-path` option to include the path for the node binary npm was executedwith.

> pure-prompt@1.9.0 postinstall-fail-instructions /home/ah/.npm-global/lib/node_modules/pure-prompt
> echo "ERROR: Could not automagically symlink the prompt. Either:\n1. Check out the readme on how to do it manually: https://github.com/sindresorhus/pure#manually\n2. Or add the following to your \`.zshrc\`:\n\n    fpath+=('$PWD/functions')"

ERROR: Could not automagically symlink the prompt. Either:
1. Check out the readme on how to do it manually: https://github.com/sindresorhus/pure#manually
2. Or add the following to your `.zshrc`:

    fpath+=('/home/ah/.npm-global/lib/node_modules/pure-prompt/functions')
+ pure-prompt@1.9.0
added 1 package from 1 contributor in 3.685s