Here, I have copied the pertinent part of the regulations:
(a) A Relevant Athlete is an athlete who meets each of the following three criteria:
(i) she has one of the following DSDs:
(A) 5α-reductase type 2 deficiency;
(B) partial androgen insensitivity syndrome (PAIS);
(C) 17β-hydroxysteroid dehydrogenase type 3 (17β- HSD3) deficiency;
(D) ovotesticular DSD; or
(E) any other genetic disorder involving disordered gonadal steroidogenesis; and
(ii) as a result, she has circulating testosterone levels in blood of five (5) nmol/L or above; and
(iii) she has sufficient androgen sensitivity for those levels of testosterone to have a material androgenising effect
(b) Restricted Events are 400m races, 400m hurdles races, 800m races, 1500m races, one mile races, and all other Track Events over distances between 400m and one mile (inclusive), whether run alone or as part of a relay event or a Combined Event.
For clarity, as used in these Regulations, the term 'Restricted Event' encompasses any Combined Event that includes one or more Restricted Events, so that an athlete who is eligible under these Regulations to compete in Restricted Events is also eligible to compete in Combined Events that include Restricted Events; while an athlete who is ineligible to compete in Restricted Events is also ineligible to compete in Combined Events that include Restricted Events.
2.3 To be eligible to compete in the female classification in a Restricted Event at an International Competition, or to set a World Record in a competition that is not an International Competition, a Relevant Athlete must meet each of the following conditions (the Eligibility Conditions):
(a) she must be recognised at law as either as female or as intersex (or equivalent);
(b) she must reduce her blood testosterone level to below five (5) nmol/L8 for a continuous period of at least six months (e.g., by use of hormonal contraceptives); and
[Note: as a special transitional provision, a Relevant Athlete who reduces her blood testosterone to below five (5) nmol/L for a continuous period starting from 8 May 2019 to 28 September 2019 will be deemed to have met this eligibility condition to compete in the female classification in a Restricted Event at the IAAF World Athletics Championships, Doha 2019.]
(c) thereafter she must maintain her blood testosterone level below five (5) nmol/L continuously (i.e., whether she is in competition or out of competition) for so long as she wishes to maintain eligibility to compete in the female classification in Restricted Events at International Competitions (or to set a World Record in a Restricted Event at a competition that is not an International Competition).
2.4 For the avoidance of doubt, there are no other special conditions that a Relevant Athlete must satisfy in order to participate in the female classification in a Restricted Event at an International Competition (or to set a World Record in a Restricted Event at a competition that is not an International Competition). In particular, surgical anatomical changes are not required in any circumstances.
2.5 For the avoidance of doubt, no athlete will be forced to undergo any assessment and/or treatment under these Regulations. It is the athlete's responsibility, in close consultation with her medical team, to decide whether or not to proceed with any assessment and/or treatment.