You need to add the as and vs query params.
Example "d0nkey.top/hsreplay/matchups?as[]=146&vs[]=344" or "d0nkey.top/hsreplay/matchups?as[]=highlander
mage&vs[]=galakrond rogue" for
highlander mage vs gally rogue
Exact names and numbers are based on hsreplay data
You can also use the bot in the discord (example: !matchups_link highlander mage, pirate warrior vs galakrond
rogue, highlander hunter)
All data is the default free data.