POSIX compliant sed making newline character

[john doe <johndoe65534@mail.com>]

Hello all,

I'm trying to use the command provided at (1):

$ sed '/pattern{N;N;a try\d10}' input-file
sed: -e expression #1, char 0: unmatched `{'

As I understanded, I should make a newline before the right brace.
I thought that '\d10' should do it but as shown above it does not.

What am I missing?


The idea is to be able to append a line two lines after a match while
being POSIX compliant.

1)
https://stackoverflow.com/questions/30099736/sed-insert-line-after-x-lines-after-match

--
John Doe