PHPBB3 Import failling at first stage

Digging into this a bit deeper has led me to this post which seems to be the same error I’m having.

I noticed that the fix was to update the repos with the latest Ubuntu version. I’ve changed this section in phpbb3.template.yml:

cmd:
          - mkdir -p /shared/import/mysql/data
          - apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xF1656F24C74CD1D8
          - add-apt-repository 'deb [arch=amd64,i386] http://nyc2.mirrors.digitalocean.com/mariadb/repo/10.1/ubuntu xenial main'
          - apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y nano libmariadbclient-dev mariadb-server
          - sed -Ei 's/^log/#&/' /etc/mysql/my.cnf

to:

cmd:
          - mkdir -p /shared/import/mysql/data
          - apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xF1656F24C74CD1D8
          - add-apt-repository 'deb [arch=amd64,i386] http://nyc2.mirrors.digitalocean.com/mariadb/repo/10.1/ubuntu bionic main'
          - apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y nano libmariadbclient-dev mariadb-server
          - sed -Ei 's/^log/#&/' /etc/mysql/my.cnf

But it looks like this is still failing because the key used is now out of date. Can anyone help me with the key so I can test this theory?