Can I contribute to traditional IRA 2019 if I work overseas and my oversea income are excluded from tax?

Can I contribute to traditional IRA 2019 if I work overseas and my oversea income is less than 100k and are excluded from paying  tax? why turbotax say i am not permitted to contributed to IRA since I do not have earned income? I do have earned income which is earned overseas and since it is less than 100k, i want to exclude it from paying tax in US since I already paid the tax in the oversea country.