Baby won’t stand on her own

My baby will be 11 months on the 27th , she just won’t stand on her own , I try to get her to stand so we can practice but some times she will literally not stand soon as I put her down she drops right in her butt she’s being lazy lol , or when she finally is standing (with my support) I try to let her go and she’ll just sit down .. she doesn’t know how to stand by herself what so ever , I have a 3-1 walker thingy lol she’ll stand with that and she’ll walk around with that but since she doesn’t know how to stand on her own or walk she walks really far from the walkers or she’ll like drag her feet 🙄 is there any ways I can try to get her to stand without support ? I really wanted her to walk for her birthday party which is next month (I seriously don’t wanna be holding her) but she can’t walk without learning how to stand without support first