Expenses incurred in securing a new line of work are not deductible, as a business or job* expense. But, the cost may (probably not) be eligible for a tuition credit. Many online courses don't qualify.
To be eligible for the tuition credits or tuition & fees deduction, the course must be taken at "an eligible institution". The school should be able to tell you if it is an eligible educational institution (Rule of thumb: if you have to ask, your school is not an eligible institution). In general, an eligible educational institution is an accredited college, university, vocational school, or other post secondary educational institution, including accredited, public, nonprofit, and proprietary (privately-owned, profit-making) post secondary institutions. Additionally, in order to be an eligible educational institution, the school must be eligible to participate in a student aid program administered by the Department of Education. If they issue a 1098-T they are probably an eligible institution.
Enter your school at the link below, to see if it's on the dept. of education list.
https://fafsa.ed.gov/FAFSA/app/schoolSearch?locale=en_EN (choose foreign country for state)
*All job expenses, for W-2 employees, have not been deductible since 2017.