Install igbinary for php7.1

Hello,
I'm trying to install igbinary for php7.1, I followed this How To (https://www.howtoforge.com/tutorial/how-to-install-php-7.1-on-debian-8-jessie/)
Debian 8 default php is installed version is 5.6.40-0+deb8u1 I have additional php installed 7.1, 7.2, 7.3 etc

when i try to install igbinary i get this error:

pecl -C ./pear.conf install igbinary
WARNING: channel "pecl.php.net" has updated its protocols, use "pecl channel-update pecl.php.net" to update
pecl/igbinary requires PHP (version >= 7.0.0), installed version is 5.6.40-0+deb8u1
No valid packages found
install failed

Could anyine please assist?
Thank you

 

../bin/pecl -C ./pear.conf install igbinary

 

i switched to folder
/opt/php-7.1/bin/
executed
../bin/pecl -C ./pear.conf install igbinary
add
extension=igbinary.so
to /opt/php-7.1/lib/php.ini
it worked
thanks Florian