The mark could be "Yong He", but not sure. It seems to be stamped rather than painted. The jar could be Qing dynasty from the decoration "perhaps",if it were not for this mark. Sometimes a hands-on inspection is the only way to decide ... Can you upload a picture of the whole bottom that is clearly showing the foot rim and any blemishes, as well as one of the top rim and a part just inside?
Is there a horizontal line along the circumference inside, in the middle of the jar, that shows that upper and lower part of body were made separately and then stuck together? Is the mark applied on top of the glaze?
