Is it permissible to combine the Maghrib and Isha prayers due to hardship and difficulty in reaching home on time, knowing that the distance is 68 km?

The distance mentioned is not considered a journey that permits the concessions (of prayer) according to the majority of scholars. However, some scholars have permitted combining prayers out of need if separating them would cause hardship for the worshipper. This is the choice of Shaykh al-Islam Ibn Taymiyyah and the preferred view of Shaykh al-Uthaymeen, who base their argument on the Hadith of Ibn Abbas that the Prophet (peace be upon him) combined prayers without fear or rain, so as not to cause hardship to his Ummah. Therefore, whenever a person experiences hardship in not combining prayers, it is permissible for him to combine them. As for delaying the Maghrib prayer to perform it with the Isha prayer as a Jam' Ta'khir (delayed combination) after arrival, this is a reasonable opinion. Otherwise, the obligation is to pray on time. If the driver refuses to stop and there is harm in leaving the bus, then each person should pray according to their situation. The fear of missing the company is an excuse that permits omitting conditions and pillars of prayer that one is unable to perform.