Must I pray sitting in public places like parks if there are non-mahram men present, or should I pray standing?

Standing is a pillar of prayer that is not waived except in case of inability. Therefore, standing is obligatory in prayer, even if a woman is in front of non-mahram men, provided she adheres to the legal hijab. It is recommended for a woman to draw herself together during bowing (rukūʿ) and prostration (sujūd) as an exaggeration in covering herself. And whoever permits praying while sitting when one is able to stand has given a fatwa without knowledge.