Why npm fails to install nessesary files in my Dockerfile?

In my Dockerfile I use both npm and php:

ARG PHP_VER=8.1\
    NODE_VER=6.14
FROM node:${NODE_VER} AS node
FROM php:${PHP_VER}-fpm

RUN install-php-extensions\
     bcmath\
     ctype\
     curl\
     dom\ 
     fileinfo\ 
     filter\ 
     gd\ 
     hash\ 
     iconv\ 
     intl\ 
     json\ 
     libxml\ 
     openssl\ 
     mbstring\ 
     pcre\
     pdo pdo_mysql\
     simplexml\
     soap \
     sockets\
     sodium\
     spl\
     tokenizer\
     xmlwriter\
     xsl \
     oauth \
     opcache