from diffusers import AutoPipelineForText2Image
import torch

device = "cuda" if torch.cuda.is_available() else "cpu"

pipeline = AutoPipelineForText2Image.from_pretrained('black-forest-labs/FLUX.1-dev', torch_dtype=torch.bfloat16).to(device)
pipeline.load_lora_weights('Keltezaa/megan-marx-flux-adult-film-actress', weight_name='Megan_Marx_Flux.safetensors')
image = pipeline('   realistic photo of  meganmarx,  wearing a band tshirt,  sitting in a cafe having a coffee, looking at viewer.').images[0]

For more details, including weighting, merging and fusing LoRAs, check the documentation on loading LoRAs in diffusers