default or selected kernelversion does not have config value CONFIG_IP_NF_MATCH_TCPMSS.
Result is shown for kernelversion 5.4.123

tcpmss match support

modulename: ipt_tcpmss.ko


Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering (replaces ipchains)
└─>IP: Netfilter Configuration
└─>tcpmss match support
In linux kernel since version 2.6.12  
This option adds a `tcpmss' match, which allows you to examine the
MSS value of TCP SYN packets, which control the maximum packet size
for that connection.

To compile it as a module, choose M here. If unsure, say N.

source code: