1. Participants must have a weight of greater than or equal to 20 kg.
2. Participant must have an age and sex specific BMI value no lower in range than the fifth percentile on the growth chart for children and adolescents.
3. Participant is able to swallow the study medication tablet.
4. Diagnosis of chronic plaque psoriasis for at least 6 months prior to screening.
5. Has mild to moderate plaque psoriasis at screening and Study Visit 1 as defined by:
6. Psoriasis Area Severity Index score 2-15,
7. Body surface area 2-15%, and
8. Static Physician Global Assessment score of 2-3 (mild to moderate)
9. Disease inadequately controlled by or inappropriate for topical therapy for psoriasis.

1. Guttate, erythrodermic, or pustular psoriasis at screening and Study Day 1.
2. Psoriasis flare or rebound within 4 weeks prior to screening.
3. Active tuberculosis (TB) or a history of incompletely treated TB per local guidelines.
4. History of recurrent significant infections.
5. Active infection or infection treated with antibiotic treatment within 14 days of Study Day 1.
6. Any history of or active malignancy or myeloproliferative or lymphoproliferative disease.
7. Current use of the following therapies that may have a possible effect on psoriasis:
8. Conventional systemic therapy for psoriasis within 28 days prior to Study Day 1 (including but not limited to cyclosporine, corticosteroids, methotrexate, oral retinoids, mycophenolate, thioguanine, hydroxyurea, sirolimus, sulfasalazine, azathioprine, and fumaric acid esters).
9. Phototherapy treatment (ie, ultraviolet B [UVB], PUVA) within 28 days prior to Study Day 1.
10. Biologic therapy:

a) Etanercept (or biosimilar) treatment 28 days prior to Study Day 1

b) Adalimumab (or biosimilar) treatment 10 weeks prior to Study Day 1

c) Other TNF or IL-17 blockers (such as infliximab, certolizumab pegol, secukinumab, ixekizumab, brodalumab, or their biosimilars) within 12 weeks prior to Study Day 1

d) Anti-IL-12 or anti-IL-23 treatment (such as ustekinumab, guselkumab, or tildrakizumab) within 24 weeks prior to Study Day 1.

1. Use of tanning booths or other ultraviolet light sources.
2. Answer "Yes" to any question on the Columbia-Suicide Severity Rating Scale during screening or at Study Day 1.
3. Female participant of childbearing potential with a positive pregnancy test assessed at screening and/or Study Day 1 by a serum and/or urine pregnancy test.