Login your EA Sports FC account with this link to check your transfer market is unlocked or not.
https://www.ea.com/ea-sports-fc/ultimate-team/web-app/
Transfer Market Unlocked Status ：
How to unlock your transfer market
1. Play Matches in Ultimate Team
- You need to engage in a certain number of matches across different game modes, including Division Rivals, Squad Battles, and FUT Friendlies. The exact number of matches required can vary but typically involves playing a substantial amount (usually between 25-50 games
2. Complete Squad Building Challenges (SBCs):
- It demonstrates to EA that you’re an active player, which can help in unlocking the Transfer Market.
- Focus on completing daily and weekly objectives as well.
For more details, you can check on : https://help.ea.com/en/help/ea-sports-fc/transfer-market-web-and-companion-apps/